Just opinions on those who tried g500 please.

I have mx518 for 6 years but for awhile there have been some glitches with it. It started to behave in strange way shutting optic on and off at random times. Which is not so bad, it's bearable but not for working in design programs or while gaming.

So I'm looking too buy a new one, but since I like the shape of 5xx series I'm sticking too these two choices. Mx518 because I have it allready and it's perfect for me regarding the size, curves, weight ect.

But also looking at g500 as I worked on laser mouses and they are fine too me and this one is from 5xx series with same, curves, size, adjustable weight ect. but I'm looking for your opinion regarding gaming (quake, single player fps'es, rts) working (design, photoshop and stuff like that)

Thank you all for opinions.