I've only had a 2008 LF250-B for a few weeks, but first impressions are good. The engine is smooth, quiet and strong, and it's fairly easy to ride, with no quirks or surprises. It's quite exposed, so would benefit from a screen if you're going to do motorway/highway runs, but nothing untoward.
I've had to do some minor maintenance, but nothing unexpected or expensive, and I can't spot any design or construction flaws. The only thing I'd note is that the exhausts may be prone to rusting underneath, so you may want to get some high temperate paint on there. Other than that, it seems like a great bike.