I actually love it. B2 can be really good against people that are getting frazzled and impatient (great for spacing out wakeups and slamming down jumping beans) and it's not too hard to land 2 in a row. If the opponent is aware of her KB requirement, they know that a 3rd B2 is gonna hurt and that's your opportunity to B3/B4 when they're not watching their feet. I kinda like the mind game behind it, no matter how basic.
Also, I need to confirm, but I BELIEVE it's 3 B2s consecutively on hit. I swear I've hit a B2, done something else that was blocked, hit another B2, got blocked again doing something else, then hit the 3rd B2 for the KB. I also think that if you get hit (again, need to confirm... this is all anecdotal and just what I feel like I've noticed) you B2 counter gets rest. Anyone know for sure on these ones?