Looked at this for awhile and finally purchased and installed. It is a bit expensive and instructions were a bit difficult to follow. The unit almost didn't fit,, wish it was a bit smaller. The relay mentioned in the instructions was not up top in my AC unit but proctor elimination I got the correct wire. The first time turning on the AC I was almost sure I was going to fry my unit. Luckily I wired it correctly and everything works fine. This was probably the single best mod done to my RV. I was able to run the AC and water heater at the same time off of a normal household outlet. Running off 15amp outlet and way gentler start, these should be on the AC from factory. Definitely recommend if you want to run AC off of a small generator.

I replaced our old 13,500 ac unit with a Carrier 15,000 ac unit, but found that the new ac was to much for my 4000 watt portable generator. Installed the softstart. (took about 45 min) and it ran perfectly. Then the big test, brought out my Generac 3000 watt inverter generator, it stated and ran perfectly for about 2 hours. Compressor kicked on with very little draw on the generator. Kept the temp in the 5th wheel at about 68 degrees for 2 hours and only used 1/2 gallon of gas. GREAT INVESTMENT.

Like many of you reading this right now, I purchased a smaller inverter generator with the goal of running the RV AC. Even if just the AC.
Then I lit the gen, started the AC and watched it overload... It just didn't register until that moment that the startup rush was so immense.
At this point I had already built a baffle box that made the generator virtually silent and that was the whole goal, stay quiet.
So... I set out on options that would allow me to stay with one of the smaller inverter generators, I was up for anything. I found this and was a little hesitant. I figured hey, it's on Amazon I'll give it a whirl and if it doesn't work, I'll return it.

Well, results ended up great.
Install- They have almost every specific ac diagram and directions step by step. If you can splice a cut power cord, you can handle the install in 10-20min total rooftop time.
Support- I can't speak on it as it wasn't necessary.
Functionality- It does what it says! The startup rush is reduced to near normal running levels.
The AC starts much smoother/quieter, I'd add it even if not for the generator aspect on future RV's.

I had a hard time finding actual data or users write-ups to help my decision so here's what I have tested for those thinking things over:
15kbtu coleman mach (2015) with softstart.
My gen: generac gp3300i runs the ac like a champ at 5000ft in eco mode with an additional 1000w in inverter and blower draw.
After success with this, my fellow RV buddies wanted to see how other small generators would handle the 15k unit with softstart so off we went...

Buddies Honda eu2200- runs the Ac great, need to watch additional load. It handles momentary overloads really well, just watch total sustained consumption. Tested@3000ft

Buddies Wen 2250- runs the Ac great, doesn't handle additional loads/momentary overloads very well. Tested@3000ft

All tests had been run in 90-95° weather.
All tests ran for at least 6 hours.

I hope this helps those thinking about it.
It allowed the dream of running my RV anywhere, nearly silent to become a reality. I attached a pic of last weekends trip to dry site on the Blue Ridge Parkway.
No longer being reliant on site power for AC, it really opened up when and where we can visit, especially with campgrounds and such so booked these days.

Installation was pretty straight forward except one confusing direction, but I called tech support, the friendliest guy on earth (Bill) answered on 2nd ring and we figured out the problem together in a matter of minutes. I can't even hear the compressor come on now. Please be advised, mine was a Coleman Mach. The number they had me look for was in the capacitor box and my number was 1976 A 613. As i looked down the list, I saw 1976 613 and asssumed that was it. Build told me the instructions a for the "A" Model were a little bit different. So I might have been able to complete the install without help if I had found the correct instructions. All in all a very positive experience. Tech support is over the top amazing. I will recommend that you NOT wait until a 105º day to do the installation.

Installed this in our new 2021 R.Pod 196. The installation instructions on-line were easy to follow. I had a question about it, opened a ticket and got a response very quickly. I called Bill and he was able to answer my questions without hesitation. It came with everything I needed, I simply needed to crimp the correct ends on the wires and plug them in and route the wires.
Now I can run the air conditioner with my Honda EU2000 generator. I am a happy camper! Thanks SoftstartRV! Note - take your time and read the instructions a few times before you get up on the roof. That will save you a few trips up and down the ladder.