To anyone who has had the Ex615 and 610, how do these compare?

Currently I have an ex610 and it's very similar to the 615 and I'm thinking about trading it for a 615.  Sound-wise are they the same?

Identical in all but casing. Expect azimuth tolerances on these to vary.

Thanks.  I'll probably stick with the 610 then because I like the silver buttons better.  Are these azimuth tolerances negligible and can they be calibrated?

Azimuth is nonadjustable. In my collection some of them have azimuth slightly off in one or both directions.

I have 2 new in the box 615s!!

I have a NIB 615 from few years ago.  Used it for few months when got it.  Nice player good for daily use but high's are not very brilliant.

If the head is 90 degrees, both sides are correct. If not, it is a dual azimuth. Adjust the FWD and REV azimuth both to 90.