It's certainly something I've fancied trying ever since I took the bike to Sardinia and shared the hotel with a group of German rollerbladers. They set off every morning, holding each other's belts like circus elephants, and did about 20 miles out and back. It looked good fun. I wouldn't rate it as an alternative to cycling, more as an alternative to running as you suggest. The problem round here (and maybe in most places) is how rubbish the road surfaces are. [Actually that's just the surfaces in town - they will probably be fine in the lanes round Cheddar.]
The main reason I haven't tried it yet is because I don't know anyone who does it and it's a lot of kit to buy and then find you don't like it.
Er, this isn't helping, is it...