I previously owned a B1 but returned it due to some problems and acquired a REFURBISHED A4 (which I got for a steal at $44 w/ free shipping and flashed with 1.34NA).
So far, I am very impressed! I have 1 gigabit wired PC, 1 Verizon router, 1 hardwired printer, 1 PS3, 1 Wii, 2 iPod touches, and 4 N clients (plus an office-issued laptop system that I connect to work using VPN). The router is working excellently. I did have to uncheck Short GI after frequent disconnects on one N client, disable DST, and a couple of other settings but the problem has been fixed with these tweaks.
I also have two HDD and a printer connected to Shareport, and they work fine.
I can stream using Tversity from these HDDs to a PS3 connected wirelessly to get flawless video. Outstanding!
Lastly, unlike B1, A4 stealths all ports.