Pros: This is a very well made board at a great price. I like the inclusion of breadboard pins and the pin-labels that others don't include. It took five minutes to add OLED support (via the U8g2 library) to an existing sketch, and now I get immediate feedback on my project from the top of the SoC itself. The OLED is very readable and ... brilliant!

Cons: It doesn't include an external WiFi or Bluetooth antenna connector. Those are almost as easy to add as to configure on a board that includes the connector, so it's not very con at all. The WiFi antenna is mounted beneath the multi-layer circuit board, and that seems to shield the antenna a bit. I measured -55dbm on this board, sitting next to a standalone ESP32 module that reads -50dbm from the same AP. That's as-measured by the chipset, which could vary more than the measured difference, but that's what I saw on my breadboard. It shouldn't be an issue for most projects. It also has a very basic battery management circuit that batteries won't like. It will charge a battery, but not at the proper fixed current, and that means shortened battery life. However, that's standard for all the dev boards that include battery support and nearly all dedicated battery management boards, so not much of a con.

This is my favorite development SoC now. It has every feature I commonly use.

Four stars v five because this board did not make a sammich when I requested one.

I reached out the the company a couple of times and they did their best to reiterate what I've already seen in the comments. No one I've emailed at that company appears to have a working knowledge of this part but they seem to want to be helpful.

I do not know if mine is defective or if the mountains of bad information out there are keeping me from getting the OLED to work. The rest of the board appears to be fine, except for an annoying amber light which never stops blinking and draining battery. I already threw away the packaging so I'm eating the 22 bucks. I still would like to get one of these working but only if I can find a WORKING part and a readable and accurate guide to this device.
Anyone out there have a working Arduino sketch for this thing? [email protected] Much appreciated.

If you aren't familiar with Github or how to "Fork" or "pull" from there, take some time to study that first. The vendor doesn't supply libraries, software or drivers for this part, rather deferring you to Github and the tiny community of enlightened ones who have figured this thing out.. Also, the library installation for Arduino is not straight forward. You have to have Python installed so you can install some other chunks from the Windows (DOS) command line. I have used Arduino for years, and this was bay far the most convoluted and difficult library installation I've seen.

No documentation, link to docs expired, unprofessional to say the least.

Leading IOT development system now! Very compact, great for the price.
Pros :
Light weight.
Comes with OLED battery changer WiFi and BLE support
Dual Core
Very attractive price

Cons :
1) Very little documentation, Some links in the product documents do not work. But Seller has provided them later.
2) Check the document before you buy
3) Device gets HOT, pulls ~150mA during WiFi activity
4) Pin 25 (GPIO) is used to connect White LED on the Board, some examples refer this as pin 5, this need to be fixed.
5) Not much examples on BLE ( or no samples from Haltec s/w )
6) Be careful with lengthy flashing time, you can brick the board. ( Read the GITHUB blogs if you need help)

Excellent little module for the price. I docked 1 star because it's 32mbit of memory, aka 4Mbyte. Still plenty for most projects. Be aware that the pinouts are not accurate at the moment in the Arduino IDE. Also the unit I received is the version 1 silicon, NOT the version 0. This is good, as there are some hardware bugs with v0.