Was just wondering if there is any performance lost, shaders, stuttering etc?

If it did, it would be incredibly minor. I use it for the screenshots and web browsing, but if you don't use any features you might as well disable it.

I haven't noticed anything of that sort myself with Skyrim. The only issue I've had with Steam Community in-game is with Morrowind, specifically, a Morrowind mod. One of the major graphic overhaul mods requires that the Steam in-game overlay be disabled when using it.

Performance, not that I've noticed. But it can be annoying. It was particularly annoying in Fallout New Vegas because the Pip-Boy was used with the tab key and you ran by holding the shift key so when trying to access my Pip-Boy while running (usually in combat) I ended up wrestling with the Steam overlay.

I wanted to enable it to take quick screenshots rather than pressing print screen and then finding those in the steam folder so I thought I would ask. If there is no quality loss then I might enable it.