Setting ASUS 68U in AP Mode

[mzn50]

Quick Question..

I get MUCH better performance going from Router mode in WIRED mode (Modem-->ASUS68U) to WIRE AP Mode (Modem-->ASUS68)

The 68U is the Wireless Hub... I disabled the Modems Wireless
I get a 30% increase in wireless and bandwidth performance..which is odd..

So my question is there any impact to the benefit of the 68U in AP mode ? compared to when in Router mode ?..

I know the NAT and UPnP is disabled along with a few other features..not sure what else may get me not doing this

thanks

Matt