I made the ST-2 list, too.
26-27mm knot diameter and 52-53mm loft (I'd call 26mm and 53mm respectively), although mine feels a dinky because of the larger handle and short loft.
I received it yesterday or the day before yesterday and only used it once so far - today.
It's a rather interesting brush and reminds me of a horse mane hair brush - the Zenith extra soft.
Unlike most synthetics I've tried, the hair has nearly no spring. If I nudge it to the side, it just stays there. There isn't much backbone to speak of.
On the face, it fels like... not much of anything. Cloud-like would probably be apt. Or perhaps "poofy."
I tried it with Reggie's Razors shaving cream, and it fared pretty well. A slightly slower start, but it hit the stride quickly and ended up producing very nice, fluffy lather, just how I like it. Perhaps even fluffier than the Edwin Jagger XL brush I have, which is one that produces good lather in a pretty short amount of time, and the ST-2 managed it in about the same time the EJ usually does.
What I was most impressed by was lather release. It didn't seem to hog lather at all, and when rinsing the brush after the shave, I managed to rinse the soap out in a jiffy.
It's clearly not a brush for those who like loads of backbone in their brushes.
I was going to say that I would have prefered a 28-30mm knot, but I didn't actually feel the brush lacked performance-wise at all, and I'm not sure there would be a benefit having a larger knot, seeing as this brush held enough lather for 3 passes, touch-ups and still had a little left over.
In fact, I'd say it performed better than the EJ XL brush I mentioned usually does, and that one's very good (except for very prickly tips, although I've learned how to deal with those).