I am running the bt57s on my 600r and have had a fine time with them. Lots of people say they are greasy or rock hard. While they may not be the best tires, they have held up for 7k and have not produced any scary moments. I do ride pretty conservatively, compared to some, but certainly do not hate them. I am due for new tires next spring at the latest. I will probably go with something else at that time. I'd at least feel better with a tire that harder-riding folks like. Might be there for me when I need it.
On last CBR600 I ran the stock bt56 tires to 14.5k and replaced them with Dunlop 220s. Had those for 4k until bike was stolen.
Guess I am pretty easy on tires, huh?