thoughts from last nights test of a used-set (jazz trio):
I swapped in a used set of Preps the night before the gig, no other adjustments.
As someone pointed out earlier, they are a very soft touch. I found myself digging in (with ease) way too much—so much so I started a blister on my middle finger, I haven't done that since my Spiros days. so that'll be an adjustment on my part.
The general 'presence' of the bass was increased, the string has a solid fundamental and a nice 'bloom' to each note, without being overly 'complex' (if that makes sense). On this bass, the E string had the most 'growl' *maybe too much (very Spiro like IMO). The D was amazing with all the things im looking for; bottom thump/mid growl/great ping to the attack (reminds me of the feeling I got from Obligatos—without the roll

). A and G were ok (with the A being closer to the D response). I like the feel of the G, both in tension and flexibility—Spiro Weich G always felt wimpy/nasally/thin to me—Preps feel solid under hand, thick in tone all the way up the neck (reminds me of Oblis again).
With that said I like the feel/tone and the general 'presence of the bass' in the room. I just need to recalibrate my attack, maybe raise my bridge a touch as I like to dig in, and adjust the post to see if I can get the same D str response across all four strings with a bit more focus.
Overall, I'd say that they live up to the descriptions/experiences here on TB. These may be my new string—if their popularity doesn't raise the MSRP.