SR850 take hell lot of time to settle down, more than 100 hrs.
Frankly speaking I got them in Feb 2014 but still had played for less than 100 hrs. I find bit of treble spike in most song.
SR 850 are open ended too so sound will leak.
IMO you avoid SR850 as they may be Uncomfortable for you due to pleather pads. My ears starts sweating within 30 minutes of use.