Cheers mboy, went down to my local Kona dealer today to have a chat about sizes. My bouncy bike is a Scott in L and the 20″ is actually closer to those dimensions than the 19″ with regards stand over and toptube length.
In saying that, they thought that either bike would do the job as you can always extend the length of the stem, the 19″ would be more nimble but for hours in the saddle for XC then the 20″ would be more comfortable but again, until you try it, you can never tell.
Would be good to get some feedback once you get it, not seen too many specs with regards stem lengths & seat tube sizes etc..looks a sweet deal though.
@CP Forgot to ask, was it a Kahuna you tried with regards comparing 19″ vs 20″ or was that in general? Kona sizes are pretty close to each other but nice to have the options