Dunno. The chipsets are radically difference. Punch in the FCCID numbers into the FCCID web site and see what's inside:
I vaguely recall reading one complaint in this newsgroup about a version 1 unit that just quit for no obvious reason.
I have a BEFW11S4v4. $5 is a great price. Try running the router exploits test at:
I suggest you lose the power booster. The problem is that you've built an alligator. That's an access point with a big mouth and small ears. The whole neighborhood will hear your transmit signal, while your receiver remains essentially unchanged and cannot hear low power client radios at the same distances. If you're going to use a power amp, you really should have equal power output at both ends of a link to insure symmetrical ranges. Otherwise, your power boosted signal is just another source of interference.
Also, going through 3 walls is somewhat of a crap shoot. You will probably get a connection, but it probably won't stay reliably connected. Perhaps you would be better off with a 2nd access point at the other end of the house (with a CAT5 cable in between).