"Complete flop" is going a bit over the top. Had some very good games for us in the first half of the season. "Never fit" is nonsense as well, as he played a part in 24 out of 25 games (excluding the suspension, and only not making it on to the pitch for the Boro game in the LC) before getting injured against Swansea. That particular injury wasn't because he is injury prone either. His knee took a hammering from a challenge. He played on, but he definitely shouldn't have done. It would have sidelined anyone.
For the price, it was a risk worth taking, and it hasn't bombed like Falcao did. At least Basti has put in some good performances, and played plenty of games. I would guess his presence off the pitch is very good too, considering when he's on it, he seems to be barking orders at everyone. Regardless of who wears the armband, it's always looked clear who the captain is when he plays.