Here are some quick q-JAYS 1st gen vs. 2nd gen. measurement over my homemade rig. Accuracy no guaranteed, but it should give you a rough idea.
The first impression is quite positive. It is definitely an upgrade over the first gen. Both share a similar tone, but the 2nd gen is more balanced with better upper detail (as you can see from the FR curve). Build quality is superb as well. While the price tag might seem a bit high consider you can get a hybrid 3 drivers for around the same price range these days, I don't feel that the SQ is lacking in anyway. Overall a job well done on JAYS' part. A full review will come later.