I just know I'm going to jinx it and regret posting, but our 31FK came with the Gen 2 and we've had no big issues. (Yet????) So put me in the "cautiously optimistic" camp for now.
We're coming up from a Suburban 6gal in our old coach, and I can see an appreciable increase in the length of time it takes to get hot water, but it can't be more that 5 seconds.
I've had two issues so far: the outside metal cover has dorked itself up and I had to do some repairs, and I had to push the reset button once.
Other than that, we're OK with the thing (again, "so far...").