I've used AirBnB, typically when traveling in Austin or the west coast, a couple of times now. I've never paid more than half the cost of a (cheap) hotel room. Many times, the host has been gracious with their time and kitchen, they have had other amenities like being close to public transit and in a quiet part of town, pets (I love dogs, and my day feels incomplete unless I've gotten to quiet down for sleep with a dog warming my feet), free internet, and they've made it easy to stay as close to my normal routine and life when it would otherwise be completely derailed. I don't have enough time or energy to battle the illness and malaise that level of disruption brings.
Obviously, buyer beware. Just like I check hotel reviews to make sure there are no reports of bedbugs, I verify the type of area that the hotel is in and what kind of crime I can expect to know what personal precautions to take, and I try to book by calling the hotel to get a handle on customer service, I do the same with places I would stay listed with AirBnB.
When I travel for business, I generally have to stay in hotels. The difference is night and day. I'm locked into whatever food is available in the hotel or nearby, especially if I don't have a rental car. This makes it hard to stay on a diet. It's tough to get exercise sometimes. Counting food, it costs three times as much to stay in a hotel. If money is not an object, that's totally your call, but I could've bought two Ikea beds for the difference between AirBnB and a hotel the last time I traveled on my own time and bill to Portland, Oregon.