I had an Ares Scar a few year ok, it's ok out of the box. The gearbox has a quick change spring set up so you can get the fps you require very easily. Downsides are the amount of proprietary parts that can make replacements difficult. In the end I sold it and got a VFC, which has a much nicer finish, and meant I could fit a BTC Spectre (which won't go into an Ares).
The EGLM looks nice but the mechanism for activating the moscarts isn't the best, it doesn't produce much leverage so requires a stiff trigger pull which torques the whole thing. I was always afraid the required force would eventually break the trigger. Again, I now have the VFC EGLM which doesn't have this problem.
For that money, I would go for the VFC or Marui. If you intend to work on the gearbox, I'd get the Marui over the VFC as the next gen gearboxes are a lot easier to work on.
