That's pretty good confirmation there along with Navs, much appreciation for that.I face lather most of the time but with the older brush, I did both. It was the brush that I learned to bowl lather with and after two or three years, I moved to face lathering.
I have yet to try bowl lathering with the new one.
I also have both sizes (current generation STF) and share nav's opinion. I'm glad that I got the 23 before the 25 because otherwise, the 23 would have felt underwhelming. Unless you really need a smaller brush, I'd skip the 23mm. Price gap between the 2 sizes is not drastic but the performance difference is, IMHO.