Boudicca I remember around two years ago going for a ride on a mtb 26" wheels after riding a brompton and a 20" folder and within a five minutes i was AMAZED how much better i.e. stable, faster, better at rolling over stuff it was relavtive to the other bikes.
granted i havent speciffically riden the llama but i have other 20" folders off road and it just wasent as fun.
the research seems to confirm its not suitable for my type of riding i.e. off road not just bad roads
http://www.bikeforums.net/archive/in.../t-376213.html
http://forums.mtbr.com/showthread.php?p=2767607