Hmmm... no posts here for a few days, so permit me to jump up and down excitedly and announce that I've just ordered a KG3925 from K2.
Many thanks to those that gave me their thoughts and info (TausCNC, Aksess and especially erik_m).
I expect delivery will be many weeks away (and I'm also looking forward to the inventive ways in which the shipping company will attempt to destroy it on its way to the UK).
I'll update as I know more...