I got my purse pinched out of my handbag in Barcelona last March. Having said that, I only had about 30 euros in it as I too had heard of it's reputation. I had most of my money and cards in a money belt, some in a zipped compartment in my bag, some in a larger bag I was also carrying. I did get my purse back (empty of all cash) by looking in the nearest bins!
Having said that Barcelona is a fabulous city, it certainly hasn't put me off going again, as the above posts have said, you can get mugged/stolen from ANYWHERE (my Mum had her purse stolen in Southport).
We stayed in the Hotel Monegal
http://www.hotel-monegal.com/ which I would definitely use again. It wasn't swish, but we were out seeing the fantastic sites ALL day and only used it for sleeping. It was nice and clean though, and extremely central.
We found 99 per cent (I'm just discounting the thieves) of people really friendly, the sites are amazing, the food great (we just walked down a side street off La Ramblas to find great restaurants) and there are some great shops.
Remember it won't be too warm in February (though a lot warmer than here!) but you'll need a jacket.
Go and have a FANTASTIC time!