At first I was pretty skeptical, with a lot of claims (gas mileage, no difference between "regular" cars and hybrids) being touted in advertisements, articles, etc. I test drove the CVT and manual versions of the Civic, as well as the Prius before deciding on the manual Civic Hybrid. I thought the Prius looked and drove a little too far away from what I was used to in a "normal" car. (all electric start start from a stop, etc.) The Civic has been great, performance isn't that bad for not having a lot of horses under the hood. I chose the manual over the CVT because again, it just felt better overall. Fuel economy is pretty much as stated, I get 47 MPG with mixed driving.
Great fuel economy, body style is within the norm, build quality is good. Feeling of peace and quiet while sitting at lights with the engine off, is actually nice.
Electric power steering is hard to get used to, not a lot of "road feel"; it's more like an arcade game. Clutch uptake and pedal feel is nearly non-existent, for some this may be a favorite. I haven't heard of anyone having to replace the batteries, but a two-year full warranty makes me nervous.