Yes there are a bunch on Reddit moaning about performance after the last patch. So if your hardware is marginal then you might think about it. I have had no issues at all with it, but then with my hardware I shouldn't be having performance issues. It's running on the same version of source as Counter Strike Global Offensive.
It's a tight shooter, more tactical than CS:GO. It has a whole heap of customized content. Skins, maps and game modes. The game has full Steam workshop support. It's never overly expensive and the devs are supporting the game with patches and new content regularly. It's a little like CoD before it became bullshit. It feels a fair bit like CoD:4 but without the kill streak BS of helicopter gunshits and other random ways to die. No exploding fecking dogs or RC car nonsence.
Just you your team mates, a real tight shooter and a whole heap of fun.