I'm currently using a Razer Deathadder, which has been a bane within the month of getting it. without trying to ramble, here are the issues I've had to deal with. Razer would not honor my warranty when I tried to have it replaced at about the 6 month mark.
Within the first month, MB4 snapped off of it's internal armature. MB4 is useless.
Within 4 months, the plug in my computer is loose and I have it taped so that moving it too much on the desk won't move the wire and randomly disconnect it. Issue not replicable with my other USB devices but with mouse in other ports, so it's definitely the mouse.
Within the year, handsweat has actually destroyed the body's "rubber" coating or whatever's on top where your hand goes; it's discolored light grey in areas and will scratch off just by rubbing it.
Within the year, the buttons double click constantly or refuse to click at all.
Within the year, the scroll wheel internals have become so smooth that It's all over the place. Forget weapon switching.
Within the year and a half, the latest issue has been MB5 flickering while pressed, which I use for VOIP. People constantly tell me I'm lagging unless I firmly press it on the lowest spot of the button. I've now owned it for almost 2 years.
So here's the thing. I'm looking at a few different mice. The biggest thing for me is a completely 100% 1:1 sensor, I can't deal with acceleration, angle snapping, prediction, that crap. My DA either doesn't have it, or it's so miniscule that I don't even notice it. The mice I've been looking at are the Logitech G400s (though I don't like the design), the Logitech G9x (great design and feel, but has a noticeable amount of acel on the hardware level), and the Roccat Savu (never heard of them, recommended to me, seem to be good in all departments). I will not be buying another razer product. There's also odds and ends I thought were interesting, but so out-there that I'm not gambling my money.
I'm curious what you guys are using or if there's better versions of the same thing. So far I'm leaning the most towards the Savu due to price and durability (albeit anecdotal).
The Avago 3090 is the best optical sensor currently in the market, the latest DA uses it with a razer-modified lens, no accel, prediction or anything. No Laser mice at the moment has 1:1 tracking AFAIK.