I guess I just don’t see any issues with either of them. There will always be tradeoffs or have we found the perfect airplane or avionics? I use to fly the F-15E with 50,000lbs of thrust. It was awesome, but could sometimes be a “pig” at heavy weights or high altitude, so they upgraded the engines to give another 5,000lbs each. You know what, the pilots said it was awesome, but it would be even better with even more thrust! We will never settle for what is available, we’ll want more.
I would be happy to have a gfc500 and I think they did pretty good with the cost vs capability tradeoff. If you want to wait for the gfc 600 to be certified for us (if ever) and pay a little more for a little more capability, that’s your decision, but I guarantee even the gfc600 made tradeoffs, so there’s probably something there we could find to complain about.