TAB...
Keep it 10mm would be my call.The Delta Elites were pretty cool guns in theri own right. m25 is correct is that 10mm is a real thumper, and I've never had that overly huge respect for a .40 (I've written that given my druthers, I'd rather have a 9mm or a .45...I'd be willing to toss 10mm onto that list).
Secondly, from a purely pragmatic sense, .40 1911s are a thorough pain in the ass when it comes to magazines. I have an STI Trojan .40, and it may be the most accurate 1911 I own. It is also an endless fight with the magazines (and overall length issues with the reloaded cartridges). Tens don't seem to share those problems.
Build back the 10!
Michael B
PS: Filming SHOT SHOW TV, I got to handle a new Dan Wesson 1911 Commander-sized gun with an Ed Brown bobtail in 10mm...VERY NICE GUN! I can hear it calling me...parenthetically, in my parts bin, I have a full-size 10mm Caspian slide cut for Novaks and a 10mm Wilson match barrel I picked up when they were discontinuing 10mm stuff. Now you've got me thinking...