I've used them for a few years now. I even continued using the "new" privately owned sportsbook.com once the publicly traded version switched things up.
Overall, it's a good operation. It's even the only book where my credit card works consistently for deposits. Usually a 10% bonus most of the time also. Reduced juice on Fridays, and the lines can sometimes be a little unique. They send out some good gifts and perks also. I have also received large payouts both by Neteller and check with no problem.
Here are the con's:
1. They do not accept wagers at all by phone anymore.
2. They can be slow to grade wagers, especially lesser popular wagers like first quarters or wagers on non-televised games.
3. Lines are put up later than other books.
4. Software is tougher to use than most books out there - sometimes too many clicks and work needed to find what you want.
5. Maximums are somewhat low and if you want to bet higher than the max, you need to do a chat session for requesting it.
I'd recommend them, but it's not for everybody. As long as you can put up with the cons and do not use them as your only out, you will be fine.