My set of ES-2a and EX-1a arrived last Thursday.
Have had some time with them. I am enjoying them. Agree with @spritzer on the ES-2a. Excellent reiteration of the original ES-1a.
As for the EX-1a, I think it is very enjoyable too. Not quite as a big soundstage as the ES-2a, but excellent transparency and easy to drive. I had tried it off the Mjolnir Carbon and currently on the 007t (with CCS mod).
And for the prices that Benson is charging for them, they are great value!