[Garfield]

A properly-set-up-for-towing Yukon Denali should tow both a 23 and 25 over hill and dale with no issue -- it will work hard in either case but not overly so. In the big scheme of things the length and weight difference...from a towing perspective...is negligable. In other words your Denali (and you) won't know whether it's towing a 23 or 25.

As far as campsites are concerned, I've ever seen one that couldn't take a 25 footer if it can take a 23. Length issues start with ~28' and above.

Bottom line: buy the trailer that you like best.

Layout is a personal thing...so I prefer not to give advice in that area...other than to suggest reading everything you can (pro and con) about each model, and then if possible, go and sit in each one of the for several hours to see which "feels" better. Again...it's a personal choice.

Good luck!