^I've never been able to figure out the slow cooker. Everything is always too dry, too soggy, and just plain overcooked.
Depends on what you put in there. For roasts, or beef cuts like round, I'd never use anything else -- there's so much connective tissue that needs to be broken down that low and slow is the only way to cook it. I also love mine for chili, red sauces, dips and soups.
It's easy to overcook stuff in a slow cooker -- low and slow still has a time limit. It's just a matter of remembering that the rate of evaporation of moisture within meat is a constant based on temperature, so you time things accordingly.
My wife bemoans connective tissue when slicing open rodents for work. I'm afraid of what she might toss into the crock pot.