2006 Yukon Denali XL - Question Extended Warranty

I know there are quite a few Yukon owners on this board and was wondering what advice you guys/gals could give in regards to extended warranties. I really wanted to pick one up when I bought it last year, but we opted not to at the time. I just hit 21K miles and I've had a few small issues that have really prompted me to consider adding an additional extended warranty. I know there are several choices out there and everybody seems to be pushing me towards the GMPP Major Guard coverage. With my current mileage it would cost me $2072 after tax and that would cover me for 4 years from today or 81K miles. My brother swears by it as it's saved him nearly $7K in the last couple years including a major issue with a seal that failed and damaged his motor. He paid $1800 for his. Any advice would be greatly appreciated.