The only Razer product I've been truly happy with was the Diamondback, which was nearly identical to the MX518 in terms of hardware. With a bit of driver hackin

The only Razer product I've been truly happy with was the Diamondback, which was nearly identical to the MX518 in terms of hardware. With a bit of driver hacking (really just substituting the vendor and hardware ID) you could run the MX518 with Razer drivers, which I did for a long time. I used Razer products since the Boomslang (with its floppy button problem, which was a material flaw, not component related). Among others, I had a Nostromo and Lachesis. The Nostromo was nice enough, but had some pretty strange glitches (it would at times switch profiles and just act really strangely). The hand-rest was coated in some rubbery thing which absolutely loved to attract any dirt and dust in the room, and ended up requiring very frequent cleaning. As for the Lachesis, there was a HUGE component flaw in the sensor, which was partially remedied by a ton of driver updates, but never fully fixed in my case. The cursor would drift, be subject to negative acceleration or simply not respond at all. Definitely not the kind of thing you'd want for any kind of input, really. What Logitech offers for me in this case is seemingly iterative hardware development, and great support. It's not flawless, it's not flashy, but it's safe and they have excellent customer service to make up for it. I'm no longer young enough to care for flashy gear. ;)