I happen to own both the S8f and the U12t sets, so there's my 2cents fwiw: the S8f, out of the box, sounds kinda wonky. It's very v-shaped, which is something you either like or dislike. Also, the BA timbre is very present on this set. The U12ts, on the other hand, have very good timbre, are much more w-shaped and sound much more natural. For me personally, out of the box, the U12ts wins hands down, if price is not of concern. With that being said, my daily driver is actually the S8f set, since they're much more lightweight (and therefore more comfortable, long term), cheaper (so less afraid of losing them during a commute) and respond very well to proper EQ targets. I actually EQ'ed my set to sound like the U12ts, since I like their FR so much; doing that actually brings the two sets very, very close in terms of how they sound. To conclude, I'd recommend first trying to EQ your set to the U12ts' target before buying, so you'll get an overall feel what you'd get yourself into. Hope this helps; never forget to enjoy the music more than the hardware!
I happen to own both the S8f and the U12t sets, so there's my 2cents fwiw: the S8f, out of the box, sounds kinda wonky. It's very v-shaped, which is something you either like or dislike. Also, the BA timbre is very present on this set. The U12ts, on the other hand, have very good timbre, are much more w-shaped and sound much more natural. For me personally, out of the box, the U12ts wins hands down, if price is not of concern. With that being said, my daily driver is actually the S8f set, since they're much more lightweight (and therefore more comfortable, long term), cheaper (so less afraid of losing them during a commute) and respond very well to proper EQ targets. I actually EQ'ed my set to sound like the U12ts, since I like their FR so much; doing that actually brings the two sets very, very close in terms of how they sound. To conclude, I'd recommend first trying to EQ your set to the U12ts' target before buying, so you'll get an overall feel what you'd get yourself into. Hope this helps; never forget to enjoy the music more than the hardware!