On CB250K, I have ridden both the 250 and the 350 (325) and would say the extra power of the 350, although not a great deal, makes it much more fun and is better suited to the chassis they share. The 250 feels heavy, the 350 does not.
Also, they are very easy to maintain and as long as not ridden too hard and the oil changed frequently, are very reliable.
The CV carbs are a pain, they often stick, but I changed mine for slide carbs which makes the bike so much better.
They are small and uncomfortable over long distances. Having said that I toured most of France on mine, would have preferred a bigger bike but couldn't afford one.
I have lots of spare parts and wish I had collected more of these bikes when they could be picked up for under a hundred quid.
