I have a Yukon and I love it! I have 2 carseats in the captain's chairs (2nd row) and a booster seat and a nine year old in the back. The third row is fairly roomy, but I will say that the middle might be a little uncomfortable. In my Pilot, the third row split was 60/40 (or maybe 70/30?), so the crack from the split was not in the middle of the middle seat. In my Yukon, the split is 50/50, so there is a crack going down the middle seat and I'm not sure how comfortable that would be. I have a 2007 which was the first year for the current model, so I'm not sure if its the same in older models.
So far, (knock on wood!) we haven't had any problems with it, other than routine maintenance. It has been a great vehicle and we plan on driving it til it dies.
Also, please be advised that a large SUV gets horrible gas mileage. I have the Denali (it has a bigger engine, so the mileage is a little worse than the SLT or lower) and I get about 11-12 mpg, 16-17 mpg hwy. For us, it was worth it- we really, really didn't want a van, but for some, that might be a deal breaker. Good luck with your search!
ETA: About insurance, I don't think an SUV vs. a van would drive your rates up. I have a spotless driving record and we pay about $60/month for full coverage that is well above the state minimum- I think that would even be less if my husband (who does NOT have a spotless record) were not on my policy. So maybe a van would drop my rates by a few dollars, but not a significant difference.
I also forgot to add that AWD is something that I never want to be without after having had it. I would assume that your winters are very similar to ours (southern Ohio), so it would be something you could certainly use in the snow.