I bought mine new in 2004. I have not had a single mechanical issue with the truck. An improperly tightened gas cap triggered a check engine light several months back, but it cleared itself. This truck has good low range power. I have had 1200 pounds of hardwood floors in the bed and have pulled a 21-foot Ranger boat with it. It pulls better than my previous full-size Bronco, but doesn't have the mid-range or top-end of other trucks. It works well within its rated capacities. I average 21 mpg, but this is because I don't drive hard. If I drove like most traffic, I'd get the advertised 18 mpg. The comfort of the seats was absolutely terrible and I have replaced the seats which helped.
Good looks. Reliability. Off-road package and rear-diff locks. Off-road capability. The tire size compared to the body size give it a nice aggressive stance
It's a moot point now since 04 was the last of the truly compact Toyotas and the Taco has been changed, but the seat comfort would be the biggest gripe.