I have the Logitech G602. I like my mice (and controllers) heavy, because I like to feel weight to the things I'm holding. The only downside I have is that it's wireless, which has its upsides, but replacing batteries is a pain. Or worse, batteries running out while in a game. Its shape makes it perfect for your grip and is comfortable to hold.
To be honest i really dont favor wireless mice for gaming but g900 is just 2 good in all aspects so i can put aside the fact that its wireless.
My first mouse was Logitech... and the one I use now is still Logitech.. I've never checked if these guys manufacture anything different that mouses.