I'd like an answer to the same question. I have a fully-loaded 2013 11" - i7, 8GB RAM, 512GB SSD - and I use it for work. It's also my desktop machine at times, docked to a TBD.
I wouldn't be opposed to upgrading to the newest 11" if there's a significant performance difference between the two models. Does half a GHz make for any real-world speed increase?
If there's anyone who's pulled the trigger and can give us some insight, please do!
Officially at the presentation, but people have reported in here that the 2015 11" also have it. It would also be strange for Apple to use different parts for no reason.I believe the SSD is only faster for the 13" model.