It will be hard for me to give that much time with them in case I don't like them at start since I'm superbusy with my hobby these days and I also do lots of mastering of hardstyle tracks for newbie so "settling in with a new headphone" is one of those things I have a hard time finding time for unfortunately.
At least these ones are used about 250 hrs or something so there's no "mechanical burn-in" to be pursued. I do know the brain-bias/old-bias plays a bit role though and it takes time for the brain to adapt to the change and I've experienced it before but sometimes you also know it's just not for you. If for example the music doesn't "capture you" when listening, it's probably not the right headphone for you. DT770 Pro was a clear example, then moving from DT770 Pro to XB500 which is a downgrade sound quality wise but I immediatly felt out of the first listen much more engagement and enjoyment listening mostly because the DT770 sounded so "distant" while XB500 was a lot more intimate and up-front and didn't have the metallic highs (ok XB500's highs aren't much different but it wasn't as apparent).
Then you might really really not like the Ultrasones if you like intimate, up front (read: small soundstage) type of sound. The Ultrasone S-Logic is known for producing a super spacious, out of head, and dare I say distant? sonic experience. I really like it because sometimes I have to take off my headphone to make sure that the signal is going through my headphones and not the speakers. That's how out of your head it is on some tracks and in those couple of moments you get a small smirk that make the audiophile hobby and putting in the money really worth it. I hope you like the SigDJs though.