We're on our second Rockwood, first our 23SS ROO HTT and now the Ultra Lite 2604. Both have been nicely finished and virtually trouble free. Without knowing the details, the only question I would have on them is are you sure you want the Murphy Bed vs a permanent bed. Seems like I remember something in the Mini Lite line that has that arrangement. We moved from our HTT to the TT this past spring because age - ours, not the ROO - was catching up and we were tiring of the extra bit of set up. Also didn't look at the specs, but if you can safely tow a unit with the permanent bed, I would take one more look. However, given the choice of the 2 you've listed, I think I prefer the 2503. Like all the storage. Didn't notice if the 25KS has 2 doors or not, but we like having 2. Pricewise, that doesn't seem bad. Our 2604 had an MSRP of $31,+ and we bought it at RVW for $20 and change. Even though it's a bit of a drive, you might easily cover trip expenses and a few more dollars if they have that in their line....seems like they do have some of the Mini Lites. Good luck, happy shopping and happier camping.....also easier.