My other suggestion is to watch your flights very carefully for any schedule changes once you have made the reservation. Delta is notorious for dropping flights and reassigning their passangers to a new itinerary. I just got off the phone with a Delta rep because they had just done this to me for our Oct trip. I had a long time on hold but was able to change flights from what I was "reassigned" to a flight time that was more to my needs without paying the flight change fee. You have to be persistant and keep repeating the "unacceptable schedule change" mantra, but it does work. In fact the supervisor rep I spoke with at Delta said that when schedule changes occur Delta wants their customers to be satisfied and will make the change without a charge. But you have to speak with a rep and can't make the change online. If you can set up a freq. flyer account, on Delta its called Sky Miles, you can link your itinerary to the account and then its very easy to check once a week or so for "changes".
It's been years since I flew with Delta, there are usually better timed/cheaper flights on other airlines. HOwever, in January I booked tickets for a trip (DSM-SFO) in June. Great times, both connections through SLC with 45-60 minute layovers. Couldn't have been better, and the cheapest tickets too. Having read the warnings about Delta here, I periodically checked my seat assignments and all was well.
3 weeks ago, I checked and not only were the seat assignments gone, the flights were too. Seems that in their infinite wisdom, Delta has done away with the DSM-SLC early morning flight, at least on Saturdays and reassigned us to DSM -Cincinnati - SLC - SFO. arriving 5 hours later than originally scheduled. I don't think so!

The other options are now flying though Atlanta - yeah, that makes sense. Let's fly from Iowa to California, via Georgia. Or via Houston on Continental. none of the options are good, but in the interest of sticking to our original plan, arriving in SFO around noon, we are now leaving before the crack of dawn on a 5:45am flight to Atlanta. Joy.
Coming home the changes weren't so bad. We now leaving at 10am instead of 1pm, but are flying through SLC with a good connection time so aren't traipsing all over the country.
In the future, I will consider Delta if I'm going east, as the flights through Cincinnati and Atlanta seem pretty consistent. Going west, I'm sticking with United through Denver, even if it costs a bit more.