I didn't read every word of this thread, so if I missed something (like perhaps the point), forgive me.
I bought my 2010 taco in 2013 for about 10% less than what a new 2013 truck was going for, and it had 12k miles on it. My biggest regret is not just getting the new truck. The tacoma is an interesting case study since they are in so much demand, they don't devalue like other vehicles seem to. I paid like 29k for my truck, and 3 years and 65k miles later I could still probably sell it for like 25k, which is crazy to me.
My plan for the last year or two has been to trade in this coming summer for a 2017. Give the new motor and truck a production year to work out the kinks and then get a new one. All of the returns I've heard from people on that new 3.5 motor is that it sucks. It's basically the toyota version of that anemic 3.8 that jeep put in the 4 door wranglers for a few years. It's more powerful and efficient on paper, but every person I've spoken to (including some toyota techs) all say it feels gutless, hunts for gears on even small hills, and doesn't get any better mileage than the 4.0. I already feel like my 4.0 is underpowered, and I don't want to get into a truck that on 33's will be wrapped out trying to do 60 over Parley's.
I'm definitely going to look at the diesel Colorado's when they land. It's a good looking truck and I think Chevy has made major progress in the reliability department. 600 mile range on a tank is super appealing, as is the diesel, but there isn't a lot of support for aftermarket suspension out there for them (yet?), and I've grown very accustomed the the lack of maintenance and upkeep my Tacoma has required in the last few years. For someone without a garage or the time to dig into even minor fix-it projects, that's a huge consideration.
I've always been a used car guy, but the older I get, the more I appreciate the reliability, warranty, and knowledge of where it's been that comes with a new vehicle. You might lose in depreciations, but there is value to peace of mind.
