This is an old thread, but maybe my answer will help someone.
I walked into a bike shop yesterday thinking I would get a MTB or hybrid. I have always ridden them and in France where I rode a lot in town, that was necessary: there were hardly any bike roads and I would get up and off the side walk constantly, crossing tramway tracks and navigating obstacles. A mountain bike is good for that, you can stand on it, slalom anywhere, stop and go with little effort/awkardness. With a mountain/hybrid bike, you are "in" the bike, it becomes part of you and it protects you.
However, the guy in the shop was having none of that and made me get onto a road bike, ahhh!! I felt uncomfortable and a bit scared as he held it and made me pedal backwards and adjust my position. I still agreed to take it for a test ride around the block but was actually a bit relieved that he handed me a helmet... I normally never bother with helmets.
Anyway, so here I was, getting not into my usual position in the bike but instead perching myself onto that narrow frame. Starting the bike was awkward, but the moment I got going it felt wonderful. I was flying over the road with an ease I had never known. I only enjoyed the feeling for a second though: the brakes, where were the brakes? I needed my brakes at their usual position. Slightly panicked, I pressed the brakes and found that I could stop, but not as abruptly as on a mountain bike. The days of racing down a super narrow street at full speed and hitting the brakes as hard as they would go at the very last second were over... then again, there are not so many narrow streets in the US.
I found that navigating traffic at a red light was uncomfortable and wondered if I could get used to the bike, so I said I wanted to take the hybrid MTB type bike that I had been eyeing. Getting on it was bliss, it was so easy and familiar. However, the moment I hit the road, I started missing that feeling I had had with the road bike, that feeling that I was flying over the road. I got up on the bike, slalomed, braking hard and starting again, finding some satisfaction in my antics.
If the MTB had been really great, I might even have bought it, but it just wasn't that good. It was an alright bicycle and would do, but I wouldn't love it. I went back to the shop and took the road bike again. The second time felt less awkward, and I was flying over the road again.
I bought the road bike and am very happy with it. One disadvantage for me is that I can't pack it the way I used to pack my old bike. I used to have a big basket it the front and a large rack with two baskets in the back. I would go to Home Depot, but tools, planks, tiki torches, etc, and then pass al the hopeful drivers with their vans, put everything on the bike and drive away, leaving them baffled. The more weight I put on my bike, the more stable it would get and even though it make the bike heavier, the effort to get it moving never got insurmountable.
On my new bike, transporting that much stuff would be unthinkable. Guess the van drivers will love my bike ;)