I used to run my CRF405x with rim locks and slime in the tube and never had a problem. I used the crf for some laning but also rallies and have a TTR600 for laning only, with rim locks and and h/duty tubes but got a puncture a while ago whilst in the Dales. when I joined the tango briggade I had mooses fitted (middle of last year) and haven't had a problem since. Mooses remove the need to carry pump, gas canisters, tyre levers etc, but aren't very cheap and some bike shops won't fit tyres onto mooses!!
My 2peneth any way
Cheers Coops