Hi, I have a TD-125/II. About a year ago, I installed an Origin Live 250 in place of the stock Thorens arm. In my system, and to my ears (and some friends' ears), the difference was minimal (I also recorded various LP tracks with each setup onto CD-R and heard little to no difference listening to these discs). If you google the 125, you'll find that many people consider the TP-16 tonearm its weak point, while others consider the TP-16 underrated. I am, to my surprise, in the latter camp. I think the OL-250 is a far superior arm than the TP-16, but perhaps not in this particular application.
Joshua
Joshua