Don't know if I would characterize it as a "rant", but your advice sure sounds good to me. I went ~1300 miles, but I like your number even better.
Don't want to hijack, but since the door is open, I believe that I also should have done the infant trans fluid change as well. I went ~2/3 of the recommended interval, and would have done it differently if I had a redo.
Even farther astray, I happened on one of those click bait "10 vehicles you shouldn't own" "click next for next vehicle" articles and went for it. We were on it, for poor quality. I bought our Z71 CCLB because of its diesel and its nameplate capabilities. It has served us well so far, but if Toyota had had a similar product (which I hear they will next year in a Tacoma) I would have bit. So, the name of the game now is driving within the advertised limits, and aggressive over service. If I get bit down the road, lesson learned....
Thanks for the kind words. I'm sort of anal about the products I use and how often I service things. This is based on a long time playing with cars as well as small to very large industrial engines and equipment. As a result, I've had input from some of the top engineers in various industries along with some unique experiences. As a result, I've never had a failure of something; and when there has been a problem, I knew the reason for it.
I have about 45,000 miles on my baby Duramax Colorado and plan on doing a transmission service at 50,000 miles. I'll use Redline D6 fluid in it when I do. I will drop the pan, clean it, and change the filter / screen as well. For what it is worth, I've also changed the rear end lube and used Redline 85W/90. FYI, when I drained the factory rear end oil, there was water in it! Lastly, for engine oil I use Mobil 1 0W/40 ESP P/N 123875 and yes, it has the Dexos 2 rating. I also have a catch can or crankcase vent filter Racor CCV 4500 on it as well as an oil bypass filter. I change it every 5000 miles. Automatic transmissions by the way are very well cleaned and deburred prior to assembly through various machines. Only about half of the engine components are deburred to that same level. So they are much cleaner after assembly, and as such have far less for the fluid to clean out.
So the dealers do try to do a good job, and most do. But I also know that not all dealers take the same care. I saw the notes about oil drain back and got a good laugh. First off, if it takes 2 hours for enough oil to drain back to the oil sump, you have some really big problems. While true, after 2 hours the level on the dipstick will be a little higher, how much higher? perhaps 1/16" to at the most 1/8". If I'm on a road trip, I'll stop for fuel, put the nozzle in the tank, then open the hood and check the oil and look at things like coolant and the serpentine belt. I also give the top radiator hose a squeeze to make sure there is pressure in the system. If the oil level is low, it will show it. If you add a quart because it said it was a quart low, and you end up with an extra ounce in it, it really doesn't matter.
Last tittle rant. If it looses more than a quart between oil changes, there is a problem in my book. There are various reasons for oil consumption, but the most common one is that people don't properly warm up their car before driving it like they're in the Indy 500. The best way I know to warn things properly is to start the vehicle cold. Wait about 10-15 seconds before driving it. I use that time to put on my seatbelt, check the mirrors, tune the radio, plug in my iPhone, etc. Then drive away and drive nice and slow. No hard starts and zoom - zoom moves. I use no more than about 1/4" of throttle and drive slowly like a little old lady until I see the water temperature get up to about half way between full cold and where it normally runs driving down the highway once it is warmed up. This warms the engine and various materials to where the clearances are within a safe range in the engine, but the transmission and rear end as well. At this point, I just drive the vehicle however I want to but avoid a full throttle move. Once it is up to temperature for about a mile, then, whatever I want to do, and I'm under complete control up until the point of impact! A nice thing on my wife's Subaru is there is an actual oil temperature readout. So I have her do this until it gets to an oil temperature of about 150F.