Buttons are surprisingly good on the MM057. I have tested and reviewed many expensive gaming mice that obviously had buttons sub par to these. The main ones are very snappy and tactile and with a medium tension—they have a small amount of unnecessary pre-travel, but still feel pretty nice to click. They are pretty loud and have a rather sharp sound to them, though. All buttons use the same standard 3-legged switch with a manufacturer I'm not familiar with. They are rated for 5 million clicks, which is not very high, but again, $10 won't get you miracles.
The scroll wheel is surprisingly good and sturdy, with a very nice texture to it. Scrolling with the mouse is light, but has a lot of tactility, and the notches are pretty well separated—I couldn't make the wheel stop between two notches. The encoder is a Boyue H-975 model.
The scroll button is a bit stiffer than the main buttons, which is as expected. It's still relatively nice to click, but a bit tiring to use excessively.
The side buttons are rather mushy, and the rear button has noticeably more travel than the front one, but overall, they are still well usable. They don't require too much force to actuate and are easily accessible, but I never accidentally clicked them. This can of course vary with each grip style.
Actuation force of the CPI changer is similar, but more tactile than the scroll wheel. It's not in the way at all, so no resolution changes should occur by the way of accidental clicks.
Mouse Feet
There's protective film on each mouse skate, which you should remove before use. The feet themselves are surprisingly good; they are smooth and provide a glide with low friction—I'm not convinced about their durability though, especially since the glue doesn't seem to be very strong.
Disassembling
Taking this mouse apart is easy. All it requires is a small Philips-head screwdriver. Three screws need to be removed—two from beneath the top mouse feet and another from the battery holder. With these out, you can simply pop the two main parts of shell apart. The internals are very plain and simple, without any unnecessary design complications.