Melvyn, why do I like K2 more than the K1 and the K3? K1 has a solid dial, while the K2 has a skeleton dial. In general I don't like skeleton dials very much. Here, however, it blends so beautifully with the revealed movement details. K3 has a moon phase, K2 hasn't. I rarely like moon phases and for my taste this romantic/nostalgic feature doesn't match the thoroughly modern design of the K-series dial at all.
Oh by the way, I have just learned that the diameter of the K-series watches is 44mm. Definitely too big for my wrist... What a pity! :-(
Thanks, Valentin