The G&G CM (Combat Machine) line have polymer receivers. $300 for a plastic bodied gun!?!... you better not!... It's a no brainer, VFC is easily worth the extra cash. The VFC classic VR16 is only $10 more, for WAY more gun. A rail is easy to get. Getting a quality metal receiver like VFC, is going to cost you. The VFC gives you a quality receiver and gearbox to build from as you progress, the G&G will not.
Like Bio said, if you're comfortable changing the rail yourself, get the Classic ($310), get the exact rail you want, and you're laughing. Depending on what rail you get, you'll probably be under the cost of the Saber. If you're not comfortable swapping out the rail, get the Saber and don't look back. The pistol grip, the stock, the rail, these can all be swapped out as desired.
You could save a bit of cash if you get the CQB version of the Saber, it's much easier to maneuver in tight spaces. In airsoft, 4" of barrel doesn't really affect range or accuracy.
Last edited by Kozzie; March 30th, 2016 at 18:59..