Depending on the year and configuration of your Yukon a 26' trailer may be pushing it. The issue isn't the drive train. You'll have plenty of power. The issue is payload. SUVs have a lower payload and softer suspension than their 1/2 PU counterparts. The payload is on the yellow sticker inside the driver side door jamb. Say it's 1300#. If your tongue weight is 750#, and your hitch weighs 100#, you have 450# left of payload. Say your wife and son combined, conservatively weigh 250#. You have 200# left. Have a dog? Subtract him, and anything else you might carry in the truck. Just something to keep in mind.
Trailers in general are not a big problem. We've purchased 3 trailers new. A pop-up in '93, had for 10 years. A Jayco Kiwi 17a hybrid in '03, had for 10 years. And our current Jayco X20E. A few minor issues when new, things like door trim not glued down, adjustments to screen doors, adjustments to brakes. Nothing major. All of which I did myself because it wasn't worth taking to the dealer for. Any other small items were taken care of during the PDI.
Your house and car need maintenance. So does your trailer. Checking for leaks, dried caulking, greasing bearings, and a host of other things. We never had anything happen that I couldn't fix. You should easily get 4 or 5 years before you have anything happen, and probably longer.
Our X20E is our first trailer with a slide out. We're in our 4th season with it and it's been working fine. I will say this, with what is for all practical purposes 3 adults, I would not want a trailer without one. Especially since you are not looking for a "camping experience". Ours is only the couch and only goes out about a foot, but man, what a difference in floor space. Before she got married our daughter went with us a couple of times and we never felt cramped.
Most of all, just have fun with it!
Chuck D.
โAdventure is just bad planning.โ - Roald Amundsen
2013 Jayco X20E Hybrid
2016 Chevy Silverado Crew Cab Z71 LTZ2
2008 GMC Sierra SLE1 Crew Cab Z71 (traded)