For premiums with normal fee is very good we can clear these strange WHOIS of circ.us sunmounta.in etc that confuse even sedo and transfer all to dynadot (my fav) or name.com or hex and manage easier.
The fact that can be transferred only to registrars that already hold prems is a big minus as marketplaces can not remove the text regarding the transfer barrier, even if i do not like at all, godaddy is most people's choice.
As for legacy premiums with higher than normal renewal fee, wrote already that so far we have the base point that if a name is not at ENOM then it has 100% normal renewal fee, so after removal of transfer barrier of legacy prems how we and buyers will know that a name at name.com, or dynadot etc has no high renewal fee if registered before March of 2010. In my opinion renewal fees of legacy prems are locked by Verisign and will be same at all registrars.