If so, what are the main advantages that you find important?
If not, what's missing that is keeping you from switching to bitcoin sites?
Yes I absolutely prefer to use Bitcoin sites for sports bets.
The reasons are simple. I don't have to register with any name, I don't have to give any private informations for payments and so on.
Bitcoin is much quicker and also cheaper in terms of transaction fees.
You choose a game you wanna bet on, send the amount you wish to risk and if you win you will get it back plus profit immediately.
Couldn't be more comfortable than that.
I'm pretty sure a few of the those Bitcoin gambling sites could become really big.