I'll chime in on the tundra end of things. granted mine is a prev generation so the info is a little dated, but we base our decisions on recent histories, and 2006 is recent enough.
The 2006 was indeed different from other offerings, and it sticks out today as a unique animal. mine is a limited TRD, and that pretty much means "simple truck with leather." the HVAC controls are push/pull cables. the wiring is not multiplexed-- there is a wire for each function. there are very few "frills" of any kind. The LSD is mechanical, not brake-actuated. Aside from the VVT, it could have been manufactured in the mid-90's.
By the looks of it, the PO was pretty hard on it. Obvious wear to the receiver hitch + a removed brake control says it towed something big. Every spot the detailer missed when it was resold was filthy---- mud caked HIGH up in the engine bay nooks and crannies. nasty funk buried in the folds of the interior.
Yet it runs like a top. And we've put it through its paces towing our TT which is very close, all said and done, to the max rating. No hiccups. Has features you don't find in other trucks, such as engine oil cooling (heat exchanger to the coolant). And anyone who's ever rebuilt a 'yota motor has probably observed that they are pretty beefy, and pay attention to quality metals, extra metal, etc..
And while the driveline seems stout, they didn't test it all the way through. sound insulation is completely inadequate for the raucous droning that fill the cab when pulling. At towing RPMs (2300-3000) the oem insulation is useless. it's a quiet truck where it normally lives below 2200 rpm, but with O/D off, the tuning is nonexistent. It's obnoxious. So-- the powertrain engineers did the normal toyota thing, but the guys in the body department didn't really see it as a priority. may be a case of, "we met the HP/towing numbers people want to see, but we don't see the majority of them doing it...." I'm considering dynamat, peal and seal, or even roofing tar soon, under the carpet...
As others have said, they are thirsty. it's not really the most comfortable thing to ride or drive in either--- it is stiff, and utilitarian. I average ~17mpg around town, but very conservatively driven with rare use of the A/C. But if feels solid and no-nonsense. Like a 1980s GM. And it seems to have steel where steel needs to be.
and nothing leaks. or even seeps. the engine, transmission, axle seals, are dry as a bone.
The newer ones, I have no experience with, can't say. I don't like the "over-muscular" looks that followed mine---- looks like something pulled off an anime art show. but all of them started doing that at the same time and I can't say much for them either. I think newer offerings have toned it down some.
I don't really feel biased -- the toyota is really good at what it needs to do. It seems a simple, well-built utilitarian vehicle. Our next truck might not be a 'yota, as our towing needs really put the truck to its limits, but for what it is, the simplicity and sturdiness stand out as positives.
