Interesting. I'm a mtb to hybrid convert and still getting used to some of the differences including the rigid aluminum fork. Some of the roads and paths I ride are pretty torn up and bumpy. I feel some serious vibration if I don't pick my path carefully. In fact, I just got some Ergon GC2 grips to help absorb just a bit of the road noise. But when I had my hardtail mtb I was protected from all this by the suspension fork which was also great for potholes and jumping curbs.

I think so much depends on the commute. If you have a <5 mile commute and don't care about a little extra exercise then they can be pretty sweet. If you have a 20miles roundtrip commute efficiency suddenly becomes a lot more important... just like people who get rich suddenly have an opinion on the captial gains tax.