I have death adder and even though it is top-notch quality at aiming: feel, maintained sliding smootheness after years of use, overal durability, performance... But sadly it lacks in other important areas:
1st) ♥♥♥♥ing wheel sometimes spins on its own.
2nd) No DPI control, you can only set 100 200 300 etc, so if you play in different resolutions and need precise DPI control you are ♥♥♥♥ed. For that reason I can only play with 900 DPI@1920x1080, no more no less. (luckily at least one playable option >_>).
3d) A stupid program called Razer Synapse must be working at all times for this mouse to function. Which is a disaster.
4th) It costs a lot. I felt like smashing this ♥♥♥♥ into a wall when I figured out these problems but investment was too ♥♥♥♥ing big for that sort of an end xD
All in all, at least its core functions for aiming are well made... For that I decided using it until it breaks down on its own. But I will never buy something from razer again - they make stupid mistakes but rise price to the highest and make a ♥♥♥♥ing "astonishing" packaging worth half of the product's price instead of fixing glitches.