Walther waited 14 years to move from the P99 to the PPQ. Consider how much the market in the U.S. changed as the striker-fired pistol with a consistent trigger pull took over. Walther tried a P99 with a "Quick Action" but this move was a false start (to put it nicely).
The PPQ was an improvement, but, as stated above, Glock and its significant aftermarket support, especially with trigger kits, was not to be challenged.
The P99 has seen wide use in European Law Enforcement. It is co-produced in Poland with Radom. But its paddle-style release made it a non-starter here.
Walther also took an unfortunate detour of a manufacturing and marketing partnership with Smith and Wesson. While we did get a SW99 in .45 ACP, there is not much else to say about this business venture. There was also one with Magnum Research. None of these pistols did not do what the original P99 already did well enough.
And the price of magazines: Walther magazines are expensive. Everyone here probably agrees 7 or 8 magazines per pistol are a necessity. When magazines are $50 to $60 a pop, and often not available, the Glock looks better everyday with ubiquitous magazines costing almost half as much.
I like the new PDP, it shows promise, but when it has better support for holsters and more affordable magazines, then I will take another look at buying one.