Moving to CO and thinking about the 3rd gen 3.5

I have had zero of your complaints living at 7000' and going above 12,000'.

 

Maybe this will help you as you think about your choice. Here’s a video of the TFL guys towing with a Tacoma over a significant hill climb in Colorado. There are other vehicles that can do this same route better, but the Tacoma holds its own.

 

Different people have different opinions

 

Either way you’ll be fine, maybe not the fastest but fine. When I lived in Leadville at 10,000’ I had a clapped out ‘87 with a 22RE 2.4 and 250k mileage, a couple mid 90’s trucks with the 3.0 all on 31” tires. In my current 3.4 ’02 I’m running 4.56 gears, but it came stock with 4.10’s on 285/75R16’s. And my ‘20 is stock gearing on 265/75R16’s it loves going over the hill. In the Springs you won’t have any problems at all. Again, you won’t be setting any land speed records, but that’s not why we drive Tacoma’s.

 

I've towed ~4000 lb through the Rockies a couple times to BC and it does just fine.
No complaints for manual transmission anyways.