Ok, first off i'll tell you no lies, i'm a begginer rider, but i know an awfull lot about breeds and the care of horses so i hope it doesn't put you off my advice.
It depends which paint horses you buy. The same with any horse breeds you get bad ones, so don't pick one with beautifull colouration if it's a bad ride. Also, i'd beware when you buy. The bright colouration of these horses sometimes makes it more difficult to spot fualts, even the trained eye will have to scan thourougly. If the owner of the horse draws your attention to the colour patterns then be extra carefull, owners of paints often try to get you to buy because of colour and nothing else. A good thing to do would be to take a vet to get a full exam on the horses, that way you can be sure.
Now, after all thats been said and done i will say that paint horses are generally very friendly and easy to handle. They are also quite good movers and look flashy in any show. So i would reccomend, just be carefull in choosing.
Good luck!