-Makes the A5 amazingly compact
-Extremely light, durable and well engineered
-Includes APE egrip.
-Must cut for A5 front lip or remove it.
-Gappy when installed over newer A5
15 word MAX in strengths & weaknesses above makes me sound like an ESL student, sorry.
At the moment mine is out getting Duracoated, so I haven't had a chance to play with it yet, though I did put it together and chase the cats around the house with it for a while. It is everything I hoped it would be- I pre-paid for mine back in 8/06, and it was well worth the price and wait. The construction, balance, and length reduction are amazing.
I highly recommend cutting off the front lip from your A-5 to install this. It gives you a little more room for your trigger hand, and I can't see any reason I would ever want to go back to a stock A-5 configuration after holding the B-5. If you're too clueless to do it yourself, Identity Crisis can sell you a B-5 with the A-5 already installed.
People with the newer powdery finish A5s have reported that the B-5 halves do not fit perfectly tight because those new A-5s are a little thicker. It doesn't seem to effect performance though. Best bet is to pick up a beat-up older style A-5 for this anyhow, since it will be mostly covered by the B-5.
People whine about the price on these, but by the time you buy an egrip, APE board, butt stock, and any kind of decent barrel shroud or body kit you're getting up around the B-5 range, but not getting anywhere near the feel of this bullpup.
I highly recommend trying one of these out. I don't think you'll be able to resist buying one if you do, regardless of price.