I graduated from a 2000 Tundra (4.7 V8 though) to my current 5.7 Tundra. It pulled our 6,000 lb trailer OK but felt like it was at its limit. It was very reliable and we towed all over for about 3 years. Nice little truck.
We bought it used at 60,000 miles and sold it at about 100,000 and it never gave us a problem except the tps (throttle position sensor) needed to be replaced at about 90,000 miles, common on Toyotas, costs about 50-70 bucks if you do it yourself. Easy to replace the tps. Agree also with the poster above; the early ones had lousy brakes.
I'm kinda in agreement with the posters above if there are rust issues. Ours was a Calif truck and being from Calif, the rust issues associated with the early Tundras are unknown here. I guess they might be common in the east where they use salt on the roads, which is not done in Calif.
I would give you the same answer if it was a Ford or Chev with 150,000 miles on it; if it runs good and you like the truck and can pick it up for a good price, I say go for it.