Our 2011 Acadia has been great, but only has 74k miles on it. I've changed out the transmission fluid twice now. super easy to do. Pull plug drain fluid, measure what came out, put back in and then run and check dipstick for correct level.
Also, we are lucky and no oil consumption either. I switched over the power steering to AMSOIL back when we got it and changed it out again about 30k miles.
Oil changes have been at 5k miles, basically when the OLM gets down to 10%. Using AMSOIL and running PF63 filters. Like stated above I found them on eBay for $3.00 a filter and purchased 10 of them.
I don't seem to have any issues with making a mess when changing the oil. I do have a Fumoto valve on the oil pan, which is nice and pulling the filter, I just put a rag around my arm so I don't burn myself on the CAT. All the oil drains down into the drip pan.
I top off with six qts. I have a bunch of UOA's I posted on in the UOA section.
My main complaint is this thing eats tires. We can't get more than 35k out of a set. Tried various different brands.