I think tegus themselves are okay but the bigger determining factor is the experience of the owner. These animals can be worthwhile to own assuming you know enough about them (obviously that goes for any pet); I wouldn't by any means call them a beginner animal, but I think a lot of people could handle one with a little experience, and I have a few friends who keep them with little trouble. I know a lot of areas are cracking down on them, but this has more to do with them being an invasive species when people illegally release them.
Definitely know your species; Argentine Tegus are known to be more social and friendlier around people, while Columbian Tegus are more aggressive and better left alone (many people who have issues with their tegus own the latter). But if you know reptiles and are familiar with their care, tegus are not bad animals to keep at all!