Help with issue no one seems to be able to answer

I have major issue. My (N150)WNR1000v2-VC is faster than 3 newer/better routers.

I've gone and bought 3 differnt routers. Netgear N300 / Belkin N750db / Netgear N600db

With all 3 new ones my speed for wireless drops from 150mbps to 60-72mbps

All 3 the speedtest.net shows MAJOR speed increase but actual use is laggy, slow, none responsive. Online game played goes from descent to almost completly lagged out

I've returned each one and gotten the next, currently have the Netgear N600db router (WNDR3400v2)

I've checked and copied settings from my old netgear to this new one. (everything I could find that matched)

Nada

I've asked dozens of "techs" no one seems to have any answers..

So basicly I assumed I'd get a bit better speeds, performance with the newer faster ones, not a downgrade

So I'm back on my N150 for now ready to return this oen too, hoping SOMEONE here might know the problem

I'm on Comcast Business class 100mb down / 100mb Up
Wireless speed test show:
N150 45mb down / 30mb up (Connected at 150mbps)
N600db 75mb down / 55mp up (Connected at 60 to 72mbps)

So the numbers say its doing better but its not.
My wife and I's games are super laggy or time out completly
Surfing web is slow and laggy
Streaming Hulu etc slow and laggy or times out)

Yet the old router does it just fine except for the occasional (once a month) needing to reset it due to it starting to bog down..

Help Anyone???