I am using 502 Proteus Spectrum and it's great. It's praised by everybody not without a reason. It has a great sensor suitable proven one of the best for competitive games, has great design, and is packed with lot's of features via logitech software. You'd better find some store where you actually can hold it and see if it's comfortable for you, but I think it's pretty much universally comfortable.
Watch some comparison videos. I heard Hero has greater durability (50m clicks vs 20m), the new sensor supposedly better performance and life span, also the cable .. but idk if they are really really worth the extra $. You'll probably buy a new mouse anyway, so does one need one that can last 10 years?