I tried them. But in order to register an account, I should have a credit card. I need to backorder a domain with my available paypal account balance since I dont have a cc.
I do it at www.TargetDomain.com (WWD), but to be frankly backorders in the .com, .net & .info are covered at 95% by the knowen snipers
TargetDomain has a quite nice successrate for .biz backorders.