I actually was quite impressed with my old marathon 308's. In fact they are coming up to 10,000km on my regular touring bike with only a couple of punctures as far as I can remember. No problems with the 308's on my partner's old recumbent. My trike made it from Adelaide to Allice springs with two punctures on schwalbe big apples. So I reasoned that a couple of extra punctures would beat having heavy tractor-like marathon plusses.

What made me so frustrated is that after testing these schwalbes so extensively, with reasonable results, their new model marathon was so bad.

I would like to try these Armadillo's that Supertick mentioned, but they seem to be unavalable in 406mm, as usual.

In answer to Vosyer, bike +panniers 15kg, gear 10kg + up to 10kg water, myself 85kg. I designed the bike and panniers myself, to put more weight on the rear wheel than the front (sometimes it is the other way around for SWB recumbents) The rear did puncture more than the front, so weight may have been a factor. Here are some more details for the curious: http://ollypowell.wordpress.com/about-the-bike/

Thanks all.