Tiny addition to the speed discussion: indeed no one rides 30 mph in average. But in most courses there are descents where also slow bikers reach speeds way over 30 mph. In these fast sections the difference of the bikes will be more than that at 30 mph.
The real time difference could be a lot more than the value calculated from the widtunnel results, at least on courses with a lot of descents (long descents, e.g. In Klagenfurt).

Edit: also on the flat with a head wind a slower biker reaches quickly a relative speed towards the air of > 30 mph