Fantastic, in fact that's one of the major reasons we chose a miniature schnauzer. We're not allergic to pet dander, but we have family that is, and we didn't want them to suffer when coming over to our house.
Min schnauzers don't shed (their hair grows instead and needs to be trimmed). They're a hypoallergenic breed, as are most terriers.
Great personality. They have chameleon-like moods; if you want to get them excited and get them playing, they'll follow your example and emulate your mood. Or if you want them to just chill out and lay down next to you, just chill on the couch and they'll emulate your mood. Good with kids too, if that's an issue.
Only downside I can think of, they can be expensive. A pure bred puppy with champion bloodlines can run up to $1000. Pure bred without the great pedigree, you're still talking $500.
But we got ours from a breeder. She was 6 years old at the time, and was a former show dog, and the breeder was just using her as a puppy factory (just cranking out puppy litters). At age 6, they reach the time for doggy menapause, and the breeder was pretty much willing to give her away. We bought her from them for $100 and it has worked out great. If you're serious, check the American Kennel Club's website for schnauzer breeders in your area, give them a call, and ask if they have any adult dogs you can take off their hands. It feels good too, because it's not quite like a rescue from the SPCA, but you're still getting the dog away from a life of living in a cage.
Here's a picture of her:
http://www.thewarpath.net/photoplog/index.php?n=143