Well, a comfort bike or a hybrid is just like it states, comfortable. A lightweight road bike will roll easier and go much faster with less effort provided your body can take the hunched over the handlebars position. I have a nice road bike that I cannot ride for very long distances anymore because as I got older I just plain hurt more and am not as flexible as I used to be. I am all about comfort and ease of traveling but like some speed too. So what I did was build myself a bike out of a super light weight hardtail mountain frame using all the most extreme comfort components available. Sweet ride. If your riding with fast groups though, you either have to keep up or fall behind and that takes the fun out of it most of the time. I tend to ride alone because of that. Your current setup sounds just fine provided your in the same age group with the same type of equipment.