Adamo - what's the difference?

THIS link describes them pretty well.

The road and race are the same dimensions, but as Derek stated, the location and amount of gel inserts and foam padding is different (more in the road, and extra gel further back on the seat where the race's gel is more up on the noses). The race model has titanium rails vs. chromoly.

The typhoon is an entirely different animal - longer, wider, with ridiculous amounts of gel & foam and is the only ISM seat with a Lycra cover instread of leather.

It's curious to mention that although the road model was intended for more upright, road riding and the race model for in the aero position, new studies (perfomed by John Cobb IIRC) have shown that the road model gives better pressure relief when in the aero/tri/TT position and the Road model is now the recommended Adamo saddle for riding aero.