I paid $880 for my SP01 Shadow1 and it appears the cost of the Shadow2 is at least around $300 more ($1179 is the cheapest I've seen so far). After shooting my Shadow2, I can't tell a whole lot of difference in the way it shoots from my Shadow1, but I like the new checkering and the higher undercut as well as the longer barrel. I also like the rear height-adjustable sight. The trigger pull is about the same as my Shadow1, but I like the looks of the Shadow2 stock hammer better. So, is it worth the extra money for the Shadow2?
I thought the best way to figure it out was to consider what it would take to make the Shadow1 like the S2 (all prices are guestimates):
Front and back strap checkering - $150
Rear sight - $50
Long slide - $? (longer barrel alone is probably around $200)
Undercut trigger - $150
Re-finish after checkering and trigger undercutting - $150
I could be way off on my pricing since I don't really know, but looking at it this way I don't feel bad for paying $1299 for mine from CZC. After seeing them for as low as $1189, I get a little buyer's remorse, but if I'd gotten it from somewhere else who knows what the accuracy would be (mine came with a target from CZC that showed a hair over 1" group). Most people who shoot competition will put a competition hammer in any CZ they compete with which is why I didn't include the hammer in the mix. While the hammer is more 'sporty' looking, it is not that good - it doesn't cam when pulling the trigger (neither did my S1), but there is a little creep before the release. It does have a short reset to the trigger, but there is some pre-travel in SA.
To be honest, I didn't think the Shadow1 was worth that much more than a SP01, but I paid around $280 more to have one, so I think the Shadow2 is worth the price over the S1 for someone who values the improvements.