To me the K3 is Hondas attempt to merge a 500 and a 550F, try and get the best of both. However it didn't. They lost the iconic tulip bulb exhausts, that lost it the character the 500 had, the seat went way OTT in a attempt to make it more comfortable and it just looks ugly compared to either the 500 or 550F, the lights went FUGLY, way too big. In order to save on parts they nicked most of them off the 550F2, same forks, same front mudguard, same clocks, that part they got right. In order to try and get past emission restrictions they had to fit PD carbs and whilst better in some respects than before they just don't work if the bike isn't used regularly, way to prone to blocked jets.
The rest of the bike is fine, the engines good etc. Given a choice I'd choose either the 500 or the 550F over it though.