Not really....
The small pest species will soon take over a tank (they reproduce like crazy!) and can seriously alter the water parameters and will end up making the tank look horrid.
The larger species that need a mate to reprouce and lay their eggs above the water line won't cause a problem with infestation, but they are messy little buggers that need to eat a lot and poo even more. I have five, and while I love them to death, I don't recommend them to someone with small tanks or someone who isn't up to at least weekly vacuumes. (I spot gravel vac every other day just to keep the tank looking halfway clean, and tear everything out every two weeks and do about a 75% water change - and that's just for vacuuming the gravel!)
For cleaning up algea, there are fish that do a way better job than any snail would. And as for a clean-up team, I like ghost shrimp, myself. They'll clean up what even the snails leave behind. Snails also need to be feed large amounts of fresh (or mushy, depending on the species) veggies in order to grow correctly and be healthy.
Snails are facinating creatures, and with a little bit of handling will come out and crawl over your hands. I think they're cool. But they are a bit more work than people think they are.