TL;DR: 6.2L V8 still potent. Still a better value than the Escalade (duh). But if passenger room is what you are looking for, get the XL (or Suburban) because the short wheelbase trucks don't work that well as a 3 row vehicles due mainly to truck packaging issues.
Being in the conversation with a MB GLS is pretty high praise.The bottom line is this: While the Mercedes GLS remains my favorite full-size utility, the GMC Yukon is second, and depending on the task at hand could easily be tops. If it involves a trailer, a couple of kids and a long stretch of interstate highway, the Yukon is tough to beat.