Ive never had a Uromastyx but I can give you some pros and cons on Bearded Dragons.
Pros: friendly, tolerate handling well, tons of personality, diurnal, they are big, very active and entertaining when under a year old, you can take them out in the sun to bask, if you have the right conditions they are very easy to keep. Out of all my pets my Bearded Dragons are my favorite.
Cons: require large supply of crickets (especially if the animal is under a year old) need a large enclosure (the recommended 40gal breeder tank in my opinion is too small) they brumate, require a fresh salad daily, must have heat and 10.0 uvb lights (which need to be replaced ever 6months) can NOT keep more then one together in a tank, their poop smells really strongly. They require vet care...a fecal should be done once every year.