When Colt originally came out with the Delta Elite I bought one, first year. I had wanted a Bren Ten, but they went bankrupt and you couldn't find them anywhere.
Anyway, I was so convinced the 10mm was superior to anything else in an auto. I read the FBI study back then which heralded the 10mm and told many of my friends about it. But what I came to realize was the 10 recoiled more sharply and made follow up shots much slower. Since most of what I expect to ever use my 1911 for is inside 5 yards, I didn't see any real benefit from the 10mm. Went back to 45's and never looked back.
I loved the 10mm on paper, but not in real life. IMHO, there is a reason the 45 has been around so long. It is the perfect balance of power, manageable recoil without over-penetration and it has affordable ammo choices.
If I had to choose one of the two, I'd probably go with the Delta Elite.