Merely from work flow considerations QU wins hands down.
Ah, Terry!
Your time zone is 5 hours earlier than mine.
Terry has nailed the number one item, Mike's FUSION interpolator.
Besides that, have you seen the comparison of USM to DFS?
... and since you are a long time user of Qimage Ultimate, I wont go into more detail, but let's re-examine the phrase, "Adobe's introductory $10 monthly subscription fee".
Even if the introductory price holds for 6 months, you rented Photo Shop from the cloud, and spent 60 dollars, and on the first day of month 7, you have nothing in your hand to use.
You can buy Qimage Ultimate for that amount (on sale), and own it!
Maybe, I have a screw missing from my Hard Drive, but I don't get it. Let's say that the answer is yes, Thery have made improvements to the algorithm.
That's all the more reason to laugh. After 15 years of playing catchup to Qimage's Quality, the big news is, *MAYBE*, just maybe, they might be getting close?.
Fred