I have a longer trip planned up to Manitoba this coming summer (roughly a 2300 mile round trip) and am currently prepping my S8 150 for long distance reliability rather than going the performance route. To me and a few other riders I know, this means checking everything twice, tuning the carburator, changing the rollers to slightly heavier Dr. Pulley items and changing the bodily fluids on a regular bases. Currently at about 600 miles (I got it in November of 2010) it will soon be on its second oil change and then starting synthetic at the third change.
One thing I found out when I was going over the bike ... there were a lot of loose nuts, bolts and cap nuts on the trim pieces, external turn signals the end cap of the muffler etc. I used a 1/4 inch drive, socket set to tighten these up and still check on all of them about once every two weeks.
This little bike was even fun in snow ... up to a point. When it got over the hubs and started to high center on ruts, well, I keep a KLR 650 around for the really crappy stuff.
Fun bike, I've been getting between 73 and 78 mpg - hopefully that will be even higher when it doesn't require a long start up time.