I have shot about 10 rolls of the Extreme 400 so far. I had previously read some bad reports online, but dev'ed in Xtol and Rodinol it seems like decent stuff to me.
Could it be rebranded HP5 or maybe some old/off spec stock co-packaged by Ilford? I have not shot hp5 back to back with the Extreme 400, but I have compared the packaging on the Ultrafine Extreme 400 vs rolls of Delta 3200. The box, wrapper, and backing paper all scream like they were made by the same people.
I also have several rolls of the Ultrafine Plus 100 and 400 that were purchased at the same time as the Extreme 400. All three have different packaging. The Plus film seems fine, but my negs have a bad curl to deal with. No curl with the Extreme 400. I just wish it were about $0.50-1.00 cheaper per roll.
What did you use for development on those example shots?