Heres a question you need to ask yourself, are you gonna be plinking and have it as a collectors piece, or are you gonna go out and play? Kitting up a gbbr with mags is really expensive when they have relatively low capacity. An AEG is a much more reliable option if you spend money on a good one, tons of upgrades, more ammo capacity with magazines, batteries last way longer than gas and gbbrs don't perform worth a shit when the weather gets cold.

I am going to take a moment to reiterate. If you reaaalllyy reaaalllly want a GBBR, get a DAYTONAGUN!!! They are simpler to maintain, operate on HPA so there is no cool down, and can use standard AEG mags, plus have all the fun kick back of a GBBR. They are a little pricey though but ultimately probably equally expensive as a GBBR if you consider cost of Mags, how many times you may or may not have to fix the gun, and time you will spend maintaining the gun

personally I'm going all Gas blow back.. with 1 exception.. I will always keep 1 aeg on my wall, just for a back up/rental/loaner gun.

I however am not going GBBR in the normal fashion... the latest influx of carbine kits for pistols lets me walk the line of both worlds... GBBR and my pistolero heart ;)