I've not ridden one, the RGV owning friend of mine had one before his VJ22, he said it was great and neither it or his RGV gave a spot of bother in years.
But they are a generation behind, thin (130*18 rear) crossply tyres as standard but there is nothing to them at under 125kg dry weight in full road trim. Minus the road kit and with a fibreglass fairing and race pipes it's going to weigh nothing, and they're dirt cheap.

This;

is a running KR1S wearing an RS250 body and spares inc WOW for £500 on the KR forum! If it'd been there before I bought my RVF...........

The thing on both the KR1 and RGV250 sides is they are full power (i.e. the best part of 60bhp) in standard form so most were left that way, especially when new.
The later KR1S was known for seizing but I'm not too sure how true that really is.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread