I have toured around 20,000km on recumbents, and another 20,000 on my regular bike. More than half the riders on our recent Beijing-Paris expedition used recumbents. I find the recumbent more comfortable on everything except steep hill climbing, and hill climbing combined with really rough roads (eg much of Kyrgyzstan) or sandy roads (eg. parts or Kazakhstan). It gets worse with 406mm wheels, but better with suspension.
The only place I wouldn't prefer a recumbent is somewhere you know you will be climbing hills all day.
Some things I watch out for for me when designing/chosing a recumbent are:
Numb feet - some people find this worse on recumbent. More important to use a high cadence. May help to avoid a really high position for the cranks.
Sweaty back - Not such an issue in cold places, but annoying in Australia.
Sore Neck - If it is too low without head-rest. Again some people have no trouble.
Pressure sores - Particularly the end of the tail bone, and the bit where the hips poke out on your back side. Maybe I have a particulary boney backside.
Arguably the last two points are more likely on a regular bike anyway.
Good luck
Last edited by wologan; 07-25-08 at 07:18 PM.
Reason: Made a mistake