Can't say I've used them before or know anyone that has. Their site sure has some good ideas on it though.
What I do know is this....I've been using BulkRegister for almost a year and the recent lay-offs made me think...wow, what will happen if they fold?
I still don't know the answer to what will happen if they fold and quite frankly I hope they don't cuz I'm sure it would be a real pain. But that brings to light the real question behind registrars.....are they solid or fly by night.
We've all seen .com's come and go lately. Honestly I would rather have teeth pulled than deal with NS sometimes but one thing seems certain about them...they'll be around tomorrow. I can't say that about some of the others.
Perhaps we can get some feedback from users of the various domain registrars and pull together some collective wisdom on the safest place to register your domain.