I've been pushing for it and now my dealer informed me he too is expecting shipments. My understanding (which is limited) of the major difference is the base stocks, ester vs. Polyalphaolefins. Ester processing demands higher costs. The bigger question is whether they work for your bike. I found a homegrown mix was best for my racebike.
A lot is made of Esters(group V), or multiples of in some circles
PAO's(group IV) are very good as well, just different horses for different courses.
Neither basestock in it's own right can deliver what's required and or expected of an engine oil.
Especially in this day and age as oil technology is being pushed to it's limits in some applications.
No one basestock is the best, and it's always a varying blend of different basestocks that delivers the goods in a "fully formulated oil".
Some essential additive packs come with group II or group III basestock as a carrier. So that contributes somewhat to making up the final blend at the end of the day as well.
The biggest growth sector at the moment in terms of technology is the group III's which are derived from a number of processes.
Shell is pioneering in one way with their GTL technology and it's possible the current Shell Advance Ultra 4T oil will be benefiting from it, where it used to be mainly derived from PAO's.
One thing is certain.
Oils will continually get better and we all will be beneficiaries in the long run