I've had problems with my Mamba quite a bit recently, with it just shutting off despite having full battery. But on the other hand it is extremely comfortable and I've never felt any lag. On the other hand the logitech G9 which I had on my laptop suffered a cable which constantly got tangled and eventually split. It had far more problems than the Mamba.
Granted the el cheapo wireless mice are rubbish compared to wired gaming mice, but a high end one is the equal of a wired mouse.