A lot of things are propritary and there are some issues (eg - selector switch), this would depend on how you treat and maintain the gun. You have more mag options with the SCAR-L. But all in all its a good gun. I run one myself and would recommend it. The one thing I would suggest is buy it brand new and not used.
ICS M4A1, VFC SCAR-L, KJW 1911A1, KWA USP COMPACT