The G502 is one of the most revered mice of all time and for good reasons. G-shift, good ergonomics, multitudes of programmable buttons, good durability, all contribute to an excellent product. I had my own G502 wired (Proteus Core, not Hero) for three years and it's been running without any problems barring the frayed fabric wire--which is mostly my fault anyway and you can just strip the fabric easy.
The G502 Lightspeed is an almost exact copy of the original, with the advantage of being wireless while still maintaining all the features of the original. As a wireless mouse, it avoids most downfalls of wireless mice. The Lightspeed has excellent battery life and next to no latency--though I don't do serious FPS gaming with it. It also charges surprisingly fast. The only downside, which admittedly is really noticeable, is that the left and right-click felt weak. My G502 Proteus Core has a solid and tactile click and comparing with the Lightspeed side-to-side made the Lightspeed's clicks felt downright unpleasant. There are also issues regarding its durability, particularly with the left and right buttons developing double-click issues, so I'll just have to hope mine isn't a lemon.
In conclusion, this is still 95% of the G502 experience without the wires. So, if you're looking for an "endgame" mouse, this will likely be it.