So when deciding between the Denali or XL I would look at the fact that you have 3 kids. You always need 3 rear seats available. If the short WB came with a bench it would be a contender due to maneuvering it around town. But if it has captains in the second row I would say no. Having one third row seat up all the time is a pain and takes away way to much cargo space. I would go with the XL and enjoy the fact that you have a ton of space available whenever you need it. Also finding one with captains makes it easy to access the third row and not have the kids climbing on seats and such. That '07 XL looks nice I'm just not a fan of the white wrapped trim pieces. The 22's are my fav but tires may cost more than the 20's although I haven't researched that. I don't know if you need AWD but if you do make sure all of these have it and aren't 2wd versions. Like previously stated saving money up front may feel better in the beginning but could cost you more in the end. Post up some XLs that are local and let's see what's available.