I've waited several months to write this review because I wanted to thoroughly test it out in the Dominican Republic where it will be primarily used.

First off, not any mw41 hotspot will work on all 3 major carriers. It has to be this model MW41NF-2AOFUS1 unlocked.
4G Lte bands:B1 (2100) B2 (1900) B3 (1800) B4 (AWS) B5 (850) B7 (2600) B8 (900) B12 (700) B13 (700) B20 (800)
3G UTMS: 850/900/1700/1900/2100 2G: 850/900/1800/1900 MHZ

Also, this hotspot also supports USSD codes as found via web browser to the hotspot's IP address. You won't find the USSD page using the alcatel link app. You need this to be able to add a recharge (recarga) of packets (paqueticos) from which you can add unlimited internet for 1 day, 3 days, and 5 days and whatever else you find when going through the USSD menu system. ( its not really unlimited as you will find there is a data cap depending on your usage). I do all this using a pre-paid SIM card. I don't want to get stuck in any monthly contracts.

This specific model will give you compatibility with all 3 major cellphone carriers which are Altice, Claro and Viva.
I have all 3 SIM cards that i juggle around depending on what part of the country I am in. Why you ask? Because not all carriers have the same network coverage.

So from what I have tested,
Altice has an excellent coverage area and excellent LTE speeds so this is what I primarily use.
When adding money to your Altice pre-paid SIM card (I use recharge.com), they offer something that the other carriers don't offer which is double LTE bandwidth for just 50 pesos more. Using the USSD page in the hotspot, I usually add an unlimited internet "paquetico" for 5 days for 139.00 pesos (2.78 usd) and the menu will ask if you want to add double bandwidth LTE for 50 pesos (1.00 usd) which i always do.

I usually get between 50 to 75 mb on the downstream and about 20 to 30 mb on the upstream. After you run out of paqueticos (internet) you will be throttled down to about 256k until you add a recharge. Let me mention here that I only pay for the 5 day plan at a time and it seems to only give about 10gigs of data to use so if you consume it all on the first day you will have to add more recharge to your account. I know it sucks but it all depends what you are using it for.
To initiate the USSD menu system for ALTICE, enter #100# from the USSD page.

Claro which is the largest carrier and probably has the most customers and best coverage map but I find their network to be somewhat unstable from time to time especially for voip calls where their network shows very high jitter and some latency issues depending on where you are. I consider Claro my backup plan if I am not within a metropolitan area or major city of the country. They also throttle down when your paquetico runs out and their bandwidth on a good day is about 20 to 30 mb on the downstream and about 10mb on the upstream.
To initiate the USSD menu system for CLARO, enter *112# from the USSD page.

Viva now is truly the underdog here. Their coverage map is no where near as good as Altice and Claro but in the major citys you will find really good LTE coverage with great speeds. I was working one day using my altice SIM when during some heavy rains i noticed my speeds dropped to 500k. I quickly swapped out the SIM card for the Viva SIM and boom! I was back up with great speeds (about the same as Claro) all while it was raining and was able to continue working. I highly recommend having a SIM for all 3 carriers just in case and depending where you will be. They only cost about 100 to 150 pesos to obtain. That's like 2 to 3 USD. When adding a recharge, the USSD menu system has an entry to pay for up to 28 days at a time for 540 pesos (10.80 usd). I haven't seen this on altice and claro.
To initiate the USSD menu system for VIVA, enter #123# from the USSD page.

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NOTES:
DO NOT purchase your SIM cards from the AIRPORTS!!!! (unless you feel like being raped of your money)
find a mall, a grocery store or anywhere else that sells them. You will need your passport to get it in your name.

Supports USSD codes (not all hotspots have this feature)

All 3 carriers throttle down when your recharge is done.

If you are from the USA or any other country where cell phone WiFi-Calling is supported, your phone will work very well through this hotpsot. No one will know you are out of town and no roaming charges and anyone calling you wont hear that international ring tone when dialing your number.

If you conduct business over the internet back to the USA or any other country and want to appear as if you are in that country, get yourself a VPN account which has many other benefits as well. (do your research)

After adding a recharge to your SIM account and activating a paquetico plan, you must reboot the hotspot

FOR TRAVELERS:
When traveling to the Dominican Republic, what I do is just before I catch my flight to DR, I purchase a recharge online using recharge.com. There are other sites but I think this one is the better one to use.
Once my plane lands and is on the way to the gate, I turn on the hotspot, log in to it via web browser and add the paquetico unlimited internet plan for 5 days and before I even get off the plane I am fully connected, phone works, full internet and business as usual.

edit 1-14-2020:
I have done more verification in the DR trying to confirm what LTE bands are actually being used and my findings show:

Altice uses LTE Bands: 2,4,5,8
Claro and Viva are using LTE Bands: 2,4,5,7
depending where you are.
This hotspot, MW41NF-2AOFUS1, supports it all.

I bought this device before going on a trip to Europe, I wanted to test it before I travel so I used Mintmobile sim card and it didn't work.
I contacted Amazon who brought the tech support on the phone line and I was informed it is Mintmobile issue.
I took my chance and I hoped it will work in Europe with Orange sim, and it did, it worked perfectly with Orange sim in Iceland, France and Italy.
We had 4 phones connected it all the time, we were using Wifi calling on our cell phones thru this device. The battery never ran out because every time we get into the car we plug it in, but I think it has a decent battery.
When We came back to the US I really wanted to use it with Minmobile, so I checked Mintmobile website and it has the direction to setup Android devices to use mobile data, and it worked. It works much better than my phone hotspot.

Here why I deducted one star, sometimes I lose connection to the internet, and the device is dead, nothing happens when I press the power button. The only way to make it work again is remove the battery for a couple of minutes and put it back then the device will work again ( note is never happened with Orange Sim, it only happened with Mintmobile sim).

For $55 it is a very good deal, especially it worked as 4G most of the time in all those countries, it used 3G only when I was in France in the middle of nowhere, so I really appreciated having internet there.

I purchased this after reading reviews that it works with Cricket Wireless. Unfortunately as of January 2021 Cricket no longer allows devices with out voice capabilities to be used on their network. They even suspended my line and I had to call to get it reactivated. Cricket is allowing users who have activated non-voice devices on the network before January 2021 to continue to use them until 2022.

This hotspot was compact and looked like it was easy to activate and available at a great price. I would have really liked to be able to use it and it is definitely not the sellers fault that it would not work for me so I gave a 5 star rating. I just thought I would provide this information for others who would like to use it with Cricket wireless.

It works as it should. No problems so far.

Beuno