Solid all around gun, the weight and durability of this gun are certainly great. Only things I've noticed are , it may perform poorly in outdoor environments when the temperature is below 30 F° due to the almost full metal construction the internals get cold, the orange break was awful to remove as most people have this issue, my selectfire wasn't quite made correctly and is a little bit loose on one side but doesn't cause any issues and the battery space is surely lacking a bit.
This gun is great out of the box but can definitely become a monster with some internal upgrades, for the price you could get or build something better but you pay for luxury of the item itself which most people understand.