I stated this in the other Tarkin thread, but to me, the only benefit to ordering from SSC is the payment plan option. If you're trying to budget several figures at once, or just budget figures with the rest of the things you need to commit money to in everyday life, the payment plan makes a big different, since you can budget for $50 a month for a few months and then the balance at shipping, as opposed to the few hundred dollars you drop all at once at shipping with other retailers.
Personally, I've never had a problem with SSC customer service, they've actually been pretty nice anytime I've needed anything, but BBTS also has friendly customer service, and their shipping rates are WAAAAYYYY better than SSC. Plus, no NRD, if you care about such things.
If you can afford it, BBTS is the better buy. I only use SSC for the payment plans and the rewards points, but I imagine after I clear out the pre-orders I have with them, I'll just use my rewards points on some Star Wars figure I want like Anakin and just be done with them.