In reply to the sheep:
> is tubeless worth the hassle when the rider can do with losing a few kg first?
On a road bike - no - complete waste of time, money, and general well-being. I tried them for two years and have never been so glad to get rid of a top-dollar purchase. Threw two nominally good tyres in the bin, donated all the sealing stuff to someone who persisted in thinking they were a good idea (Ghetto inflator, syringes and little tubes, valve core extractors, several bottles of sealant, sense of humour). That list tells you all you need to know.
Soggy, off-road pressures - maybe.
Post edited at 11:43