Yes, Sibername has the best post-TBR payment & domain assignment, but they still don't have any useful bulk domain tools or default DNS settings, etc...
And I'm afraid that WHC is going to completely f-up the good parts of Sibername when they eventually migrate that functionality into WHC's current account interface and then shut down Sibername. The WHC system is just brutal to deal with. For a hosting company, it looks horrible that their own website is SLOW AF. I really don't look forward to that day.