Pros: Over the past 8 or so years, I have had 3 of these mouses. None of them have broken on their own - One broke during a move and my last one got knocked off the table onto the wood floor by the wife.
Summary: I bought a few of the original Explorer 3.0 mice ten years ago when they came out, and used them for many years until the left-click buttons wore out. This reincarnation does not have the same build quality as the originals, but isstill a better mouse than most others in the price range. They are large and lightweight, which depending on your preference can be good or bad.
Pros: Solid everyday mouse at a reasonable price. Decent quality for the price. Large, ergonomic shape fills your hand and is comfortable to use for long periods. Includes PS/2 adapter just in case you need one.
Cons: Cheap feeling plastic. Two side buttons are loose, but seem to function OK. Scroll wheel feels "clunky" when new but should get better with use.
Summary: It's a wonderful mouse, but surely not for everyone. If you buy into the whole Pro-gamer mentality of weighted mice, super high DPI, and whatnot, this isn't this mouse for you. If you're more of a simple person who wants a versatile, reliable piece of equipment, I highly recommend this.
Pros: I've used Logitech's fancy new mice and even some from Razer, but in the end I always come back to this one. So far, I've gone through about two of these over the past ten years. Not because they break, but because the finish starts to wear off and I like to have it looking somewhat new. Honestly, I think I could still be using the first one.
Cons: The side buttons can be a little odd to reach for, but this is because I rest my thumb rather low (just touching my pad). I have to think a bit to use the side buttons; however, I have completely unbound them as I have yet to find any use for them on a regular basis.
Summary: This mouse is a 450 dpi mouse. The reason that you would get this mouse as a gamer is because of the optical engine that takes 9000 frames per second. This feature in my opinion is much better than having extremely high DPI since DPI only measures how much you have to move your mouse to go a certain distance.
Pros: Good tracking on almost any surface. Non stick feet are very smooth. Side buttons are not as big as I thought they would be. I was worried that the side buttons would be ridiculously big like the Microsoft D58-00032 and therefore hamper web browsing but I have yet to be taken back a page while using this mouse.
Cons: Mine came with a broken mouse wheel. I just opened up the mouse and super glued the part that was broken. I guess that's the cost of buying something OEM. The buttons ( All of them ) need to be pushed a little harder but that's not really a big con since the force needed is so trivial.