Kathnunley,
Congratulations on the comp at NW.
I used to fly out of MHT. It is a good little airport. You can fly to almost any major hub east of the Mississippi and Southwest is there to keep downward pressure on the prices. It sure beats BOS unless you want a non-stop transcon.
Indufan,
Yes there are alternatives to DL in CVG and they are easier to use. You can go from curb to gate in 10 mins. because every other airline leaves from Terminal 1 or 2. The good news for you is that you can always fly from IND or Maybe DAY.