Anyone have any success with this stuff for speed?

I read the article on XR-1 over on Ed Buffaloe's unblinkingeye.com and thought I'd give it a try to see if I could squeeze some more real speed out of Tri-X than I'm getting with Acufine (EI 640 for a nice looking neg). So I tested it with TXT 4x5" at various speeds and development times in version "B", both 1+1 and stock, and I'm getting shadow detail at EI 1280, but the results are kind of flat compared to Acufine. The best neg I got was with 1+1 at 86 deg. for 20 min--printable, but flat. I tried the stock solution, which is recommended for push processing, but this resulted in high base fog, I'll probably try again at an even higher temperature (up to 105 deg. is possible) and maybe a longer processing time, but even at 86 degrees, the emulsion gets fragile, and maintaining 100 deg. for 25 minutes adds another challenge to the process.

Here's Ed's article:

http://unblinkingeye.com/Articles/XR-1/xr-1.html

Any other experiences?