Kind of subjective.
Both are good examples of newer model designs from a couple of the major manufacturers.
While I don't own the Walther P99, I own a couple of the licensed S&W SW99 traditional double action models (think Anti-Stress) chambered in 9mm & .40 S&W, and I carried a similar standard SW99 .40 S&W for a few years as an issued weapon. I also own a M&P 45 (Earth Brown w/thumb safeties) and a M&P 40c (I ordered the compact without the thumb safeties). I really only ordered the M&P 45 w/thumb safeties because I own several 1911's and thought I'd get the M&P 45 set up with thumb safeties like my 1911's.
I've been through 3 armorer classes for the SW99/P99 and an armorer class for the M&P Pistol, so I have kind of a basic familiarity with both designs.
I like both designs.
I do have a personal preference for traditional double action pistols (DA/SA, if you'd prefer), and the 99 series has a pretty decent one. I don't care for the QA (Quick Action) myself, but again, that's strictly a personal opinion.
I found the M&P's unique trigger design to be fairly easy to adapt to, although the trigger in the .45 model is heavier than the standard one in the 9/.40 models (7.5lb +/- 2lbs for the .45 models, I'm told, versus 6.5lbs +/- 2lbs on the others), and mine is on the heavy end of the range. The inherent practical accuracy makes up for the heavy trigger, though. Very surprising inherent accuracy. The M&P 40c has a lighter trigger and is also very accurate.
While I won't be getting rid of my SW99's in the foreseeable future, and I really enjoy shooting my 9mm compact model, I won't be adding any more of them to my working collection, either.
The factory warranty for commercial pistols is one year from Walther for the 99's, while the M&P's have S&W's respected Lifetime Service Policy
http://www.smith-wesson.com/webapp/w...ectionId=10504
Several design features of the M&P are interesting.
Enhanced frame strength (w/steel sub-chassis)
Frame rails are easily replaced if damaged (without frame replacement)
Heavy slide dust cover to resist damage if dropped
Beavertail grip frame to reduce potential for slide bite
Grip inserts include palm swells as well as back strap differences
Ambidextrous slide stop lever
Reversible magazine catch button
Large, robust extractor
Stainless steel recoil guide rod assembly
Beveled barrel hood
Through-hardened stainless steel barrel & slide (no zone tempering)
As an armorer I don't mind supporting either design, and each has its own advantages/disadvantages ...
99 series parts come from Germany. Sometimes when I've called for parts I've had to wait because they were on back order from Germany.
The 99 series sear housing blocks are a bit complicated and expensive. The ejector is molded into the housing block, so if an ejector breaks you have to replace the whole housing block. The ejector can easily be replaced as a separate part in the M&P.
The standard plastic rear sight bases on the 99's are only held in the slide by a plunger which is held in place by one side of the windage adjustment screw. The top 'prongs' of the plunger can be broken with less of an impact than some folks might expect, and this can result in the rear sight base shifting.
The slide's plastic rear end cap is somewhat thin on the 99, while the one of the M&P is thicker.
I do like the 99's striker safety block. Unique design. Easy to remove & replace (as long as the armorer doesn't reverse it ). I also like their striker return spring idea (which is also used in the M&P).
The striker spring used in the QA is heavier than the one used in the AS. No big deal, but you don't want to mix them up if you have both models in use, since putting the one used in the AS gun in a QA gun may result in light strikes. You don't want to mix up the trigger bar guides between the models, either.
The extractor is a drop-in part on the 99, and it's easier to remove & install. It's a fitted part in the M&P and the solid extractor pin is not easy to remove ... although the .45 models use a roll-pin (part of the military spec submission when the .45 model was being developed for the anticipated military trials). The M&P extractor, on the other hand, is very large and robust (we were told it was intentionally designed to help resist hook damage in the event of a case failure-to-extract where the user might have to try to re-engage the case rim).
Removing the locking block to repair a damaged/worn slide stop lever spring in the 99 series is not an easy task because of the nature of the rolled steel pin used and its very tight fit in the locking block. I've heard of LE 99 series armorers who won't attempt to remove and replace the locking block pin in the 99 series, but return the guns to the factory if a repair requires removal of the locking block (I've removed & replaced a number of them, even outside of the classes, FWIW). Rolling over the edge of the pin by improper removal/installation of the pin can potentially cause damage to the frame, too, such as wallowing out the frame hole.
Sorry. That's probably more stuff than you wanted to know, so I'll stop rambling. I could write more, though.
Bottom line? Both are good quality pistols. I suspect that commercial owners and users of either would be well served with either choice.
Like I said, I'll be keeping my SW99 models. I've had to replace a couple of parts, but they've given me excellent service after doing so. I have a friend who has fired more than 50K rounds through each of a pair of SW99s chambered in 9mm & .40 S&W. I finally had to replace a sear housing block in one of them (broken ejector) at about the 50K mark (covered as a warranty parts replacement by S&W, too. ).
I don't worry overly much about the occasional refinements and revisions to a new model line ... but I also try to wait at least a year after a model has been introduced before I spend my own money on an example, too. Glock is still making revisions, refinements and upgrades to their model line, you know. No big deal ...
I do think S&W has a winner on its hands with the M&P.
Just my thoughts ...
