Well, so far, I have having been making my upgrades sans two exceptions and there was pretty good reason for that but I am STILL WATCHING.
I live between CVG and IND and have to fly out of IND most of the time because or price but I know that on my return if I get to CVG and things go bad I can always take a trip to Avis to get home. My second choice is NW but the closest I can be to home is DTW which mostly rules out a rental.
B/E cabin to some of my more frequent destinations, SEA, PDX, and LAX. I get to SLC a lot and the hub operations help me there. General domestic widebodies are a plus for me.
The CRJs that I have to fly are on generally short flights and Comair has no turboprops, something I am not scared of but it certainly has a slight safety issue.
Believe it or not, the relative ease that I have had in redeeming miles for award travel. I am certainly not a person that has redeemed a lot but I am sure I will get to be an old pro at that sometime.
I think Delta technology is some of the best in the business and I think they keep trying to add new features. If anyone from Delta, what I want is to keep the logged in status from timing out and automatic flight notifications from saved iteneraries.
I wasn't sure the MQMs would work for me but so far they have.
I know them like the back of my hand both from what I have personally gained from experience and from what I have learned from others here. FT has helped me a lot be a more informed traveller which means that I mostly know what buttons I can push with Delta and when. When irregular operations come up, I know I can get what I want...and the *VIP airphone service is a great service to me, even if it is not used very often. I generally get exceptional service from front line employees and 90% of the phone agents no matter where they are from, though I don't think I have reached India much.
Now, since you asked, things that trouble me.
I want K+ fares upgraded at the time of booking. EVEN if the availabilty is more limited. Afterall, at that time, I can always pick another flight. Then at the 100 hour mark, it would be nice if they cleared there. I don't like the pressure of waiting out the upgrades. This DOES cause me stress and I don't like stress. Yes, I know I am spoiled.
Specifically for me, I need a late night flight restored from CVG-IND. Post 9-11, it is nearly impossible from me to get home on the same day of my last day of work and have to spend an extra night and fly home the next morning.
All of the IFE doesn't work a lot and the staff NEVER knows anything about how to correct it. It never fails that the music that I want to listen to is the one (or two or three) channels that don't work. The B/E stuff has quite the wear and tear on it.
Maybe I will think a little more about what I want improved. I know there are international issues that I don't like (no sameday upgrades, it's just stupid) but so far, I haven't ventured there.