Originally Posted by MaciekA
To put it lightly, you've been reading the wrong reviews... G&Ps generally require replacing some key components before they're really ready for truly reliable service. That said, once you get good gears, correct AoE, throw in a decent piston, and possibly toss out the lacklustre M120 motor you'll be good. These are all cheap changes to make. The key to a good running platform is the effort and attention to detail that you put into it.
Don't worry about accuracy from one stock gun to another. All stock guns generally are generally OK when it comes to accuracy or distance, though I will say the G&Ps are decent for stock guns. You can HUGELY improve both distance and accuracy yourself after buying by simply changing your bucking and/or nub (example: the PDI W-hold). Optimize for other things like good manufacturing, TM compatibility, neodymium motors, good externals, etc.
The easy solution for this is to get a good "project gun" M4 like a G&P C8 or a King Arms M4 and turn it into a MOE build. You can get the MOE handguard, pistol grip, sights, stock, etc as aftermarket upgrades. I'd focus on a good base instead, especially if you appreciate mechanics. At the same time, the G&P MOE isn't perfect, but it is an absolutely solid project gun. You can fit a large battery and mosfet into the front handguard, the gearbox shell is super compatible with pretty much every aftermarket part out there, the airseal nozzle is excellent, and the receiver is superbly-made and painted. It's also easily modified for even bigger wiring, etc.
Masadas, 416s, etc are a royal pain in the ass for you if you want to improve/maintain and generally grow with your gun over time and have no love for searching for parts/etc. Proprietary gearboxes, hopups, and especially nozzles are by far the quickest way to kill your interest in airsoft. People who are in love with alternative guns are going to try to convince you otherwise, but it's true: You're far less likely to work or be able to work on a gun that has rare or tricky parts.
In contrast, sticking with a nice standard highly TM-compatible M4 (like the KA M4 or any G&P M4) is going to make your life very easy. In addition, if you're mechanically-inclined, they're far easier to work on and learn about internals.
Good luck.. Keep asking questions