First a vid from someone that loves the S&W M&P OTF.
So here's my days carry impression of the $40
S&W M&P OTF -
1) This is not a double action OTF. The mechanism is a side cocker (instead of an end cocker like the HALO) single action OTF like the Robbie Dalton Cubids, but with the cocking tab on the button side of the handle. Instead of incorporating the mechanism to unlock the open blade into the OTF trigger button it uses a separate locking mechanism on the opposite side near the mouth of the handle. Another piece, but another separate action to unlock it. It is easy to pull the blade back into the handle, but then so were the Cupids and the Paragons.
2) It releases the blade easily with a push forward of the machined Al button, but you have to make sure you keep fingers out of the way of the cocking tab or it will catch and slow the blade's movement forward and prevent engagement of the lock open.
3) For $40 I'm impressed by what S&W produced, but AUS 8 isn't exactly the most exciting steel. Still, what do you expect for $40.
4) It came sharp and I used it to cut tape open on packages, plastic on flats of water. Dunno how long the blade will stay sharp in use, but, again, for $40 you don't expect S30V performance.
5) It is a bit heavy for the size. I attribute that the the steel frame in the middle of the Al handle slabs. The knife is a 3 piece handle and I think S&W decided to use a subframe in steel to help ensure that the blade and mechanisms had a solid wear resistant frame to run in. The size is good and the shape is a sound ergonomic general "dog bone" design. Fit between the steel subframe and the Al handle halves isn't perfect, but for ...
6) Lockup isn't Microtech, Hogue, Benchmade, Heretic, Parana, ProTec, Guardian, Paragon, Hawk solid, but for... You get the picture. They're also a LOT more expensive, but you'd expect that. The steels are higher alloy than AUS 8, but you'd expect that. In the same $40 price range is the AKC F16 DA in Al and 440A which is fun and makes the side mounted button into a guard like look. Cool Italian OTF DA in 440A vs S&W SA in AUS8? Style vs. utility...wait, I'm talking about a $40 OTF so I'm not going to overthink utility. Still, AUS8 should be a bit better hardness and edge holding than 440A by a nudge.
Is the $40 S&W M&P OTF good enough for $40? Sure thing, but I wouldn't assume it will hold up in day to day use like my Hogues or MTs or ... nor does it have the fit and finish of the much more expensive OTFs. BUT for $40 it is a fun OTF that will open envelopes and cut tape (I haven't tried cardboard) and plastic film packaging (I may try it on some blister pack plastic). Is it comparable to the Ultratech or Hogue...
but for $40...