I've got 2 Gen 3 Glock 27s & 2 Gen 4 Glock 30s. I don't use the modular grip back straps & even though I'm a leftie I'm fine with the Gen 3 non-reversible Mag release, I use my index finger. I as well think overall Gen 3s are hard to beat. I don't even know what Gen 5 is about LOL.