From my point of view:
(please excuse the table, these forums don't provide much functionality)

	PoW BTC Pros		PoS CP Pros
	Large amount of hashing power to ensure security Early mover adoption advantage (fairly widespread) Piggyback on media exposure Legitimacy boost (via bitcoin legitimacy) Can switch between BTC and XCP without exchange		Large amount of hashing power unnecessary (more security from less energy) Environmentally friendly (forward thinking) Blazing fast transactions As much OP_return space as we need No large blockchain to turn away early adopters Instead of designing the protocol to work within the scope of bitcoins protocol, we have the freedom to develop without limits IN CONTROL OF OUR OWN DESTINY
	PoW BTC Cons		PoS CP Cons
	Slow Transactions Must buy BTC to use XCP (just one more middleman to go through) Paying tx fees to third party (instead of ourselves) Must sync non-CP related transactions (13GB blockchain at start) At mercy of bitcoin developer whims (Protocol could be rendered invalid without notice) NOT IN CONTROL OF OUR OWN DESTINY		Can't switch between BTC and XCP as easily (must use an exchange) I honestly can't think of any other downside (security was the only real downside mentioned and that point is moot with a PoS blockchain isn't it?)

+1
Nice, analysis. Something we should keep in mind if and when the time comes for the move off the bitcoin blockchain.