My previous mice include the Razer Deathadder V2, Razer Basilisk V2 X Hyperspeed, and the Logitech Pro X Superlight.
This is easily the most comfortable mouse I've used, the contours feel perfect and the extra button the side is well placed and feels like a natural addition. I've personally not found the weight an issue, though it is much heavier that most other mice, even ones that use a AA battery. I do prefer the external battery as I disliked having to plug in my mouse every so often to charge it, something that became much more frequent as the internal battery lost capacity.
The new switches feel excellent, a noticeable improvement from the V2. Performance is good in all areas with the exception of the scroll wheel, which feels like it eats inputs for breakfast lunch and dinner. Basically when scrolling fast the Basilisk V3 seems to skip inputs. My V2 had similar issues and eventually I had to replace it when the scroll wheel started acting haywire and scrolling on its own or backwards. Something to keep an eye on.
Appearance is unremarkable. The new RGB scroll wheel is appreciated, but fairly simple in customization. I have it set to static color but you can have it be reactive to clicking, color cycle, breathing, or a few other options with Razer Synapse.
One small quirk is that if you have auto sleep on, it takes a bit to actually turn back on when using it again. Whereas the Razer Deathadder V2 was near instant in my experience, the Basilisk V3 takes a few seconds to get going, which sounds like nothing but does make a difference when it happens so often.
TL;DR - It's a really good mouse at this price point, good performance and great comfort. Only negative is the scroll wheel and the weight if that matters to you.
