The bikes were technically advanced for their time, ecu, air mass meters, Hall effect sensor ignition, but you have to watch certain things, the 4 cylinder models can have ignition coil problems, spare parts can be a problem, but Motobins is usually a good bet, or ebay, the reason they do not fetch good prices is because of the technology & the fact that second-hand parts such as above can be expensive too.
There is no kick-start a retrograde step in my humble opinion and if the starter relay points stick, if the charge in the battery gets low the engine will constantly turn over and flattened the battery to dead.
But the worst thing about the "K" series is the thickness of the wires in the wiring loom, otherwise you get a smooth capable adequately powered sports tourer with not bad miles to the gallon, that handle better @ speed than when ridden slow and they are quite weighty, some would say top-heavy, there are 8 valve and 16 valve variants but The Flying Brick website is good for background information. There are 3 cylinder K75's also, some say a sweeter option that the 4, but of course you get less power, 75bhp claimed!
Cheers
John
JBW