I had thought the QA trigger was similar to the Glock, Kahr, USP LE and every other prestaged DA triggers- long and light.
The P99 is Walthers opportunity to market a pistol with a higher profit margin, like Glock, Steyr, USP, XD, CZ100, Kahr P9. The gun may work well, but it cost half as much to make as a similar metal gun. Keep that in mind when you pony up $600 for one.
There is nothing wrong with the P7. It will do anything any other pistol will, and most better. No other weapon offers that combination of reliability, fast handling, compactness, safety, accuracy and fast followup in a single weapon. If you care for it, it will likely never, ever jam and will shoot like a target gun the whole time.
The few downsides to the P7 are nit-picky and unimportant compared to it's pluses. It is the standard that all pistols should live up to. If you can stomach the initial cost, it will never let you down. I would sell everything else before I'd part with mine.