XCP is more like MSC than Nxt. Nxt is an altcoin having its own blockchain, but XCP is based on bitcoin blockchain just as MSC.
The benefit to have its own blockchain is the low level protocol can be designed from the scratch to make all high-level protocols easier to be implemented and parsing more efficient. On the other hand, the benefit of basing on bitcoin blockchain is there's already secure hashing rate and a lot of users are already using bitcoin. Moreover, implementation is easier since there's no need to worry about all those mining things.
BTW, one large advantage of Nxt is it's transparent forging (mining). According to what the dev said, it can help to make 51% attack almost impossible. I'm sure everyone agree that 51% attack is almost the pain of bitcoin and all its copycats.
Thanks. What about comparison to MSC?
If Mastercoin is the most apt comparison, you may want to review the questions stslimited has been raising about Mastercoin over the last few days in this (Mastercoin) thread:
https://bitcointalk.org/index.php?topic=265488.2780. It seems to me, at least at first glance, that his concerns may have some relevance to Counterparty as well.
Questions like: what is the functional difference between 10 XCP or 1 XCP or .1 XCP? How many XCP would someone actually need to use any aspects of this additional protocol layer? What would require someone to spend XCP or go get more XCP from the open market?
Actually this is a very good question. For all us investors, especially those who want to see the price of XCP increase 10x or even 100x, to understand the demand of XCP is very important.
Let's check the feature of XCP one by one.
1) issue and order
If I am not wrong, any issue can be priced either in XCP or BTC. If an asset is priced in XCP, then the orders can be matched and finished immediately. For BTC priced orders, BTCPay message is need to finished the matched order. Therefore, it's possible people may prefer XCP priced issue to BTC priced issue due to instant transaction. If the XCP price is relatively stable, people may buy certain amount of XCP with BTC in beforehand, and then use XCP to buy assets instantly.
2) dividend
It seems the dividends have to be paid in XCP, unless the dividends are paid outside of the exchange. Therefore, the asset issuers most likely will buy XCP for distributing the dividends.
(Actually, I am not sure about this. If there're good 3rd party software support, it is equally easy for the issuers to pay the dividends in BTC, because they have all the investors BTC addresses. The exchange has to provide more convenience to attract more issuers to pay dividends in XCP instead.)
3) broadcast and bets.
It seems betting fee are all in XCP, so people need XCP to make a bet.
Therefore, to some extent XCP is like the token in a casino and BTC is like the money, but the supply of token in XCP exchange is limited. If there're more issuers, more (bet) users, and more BTC go into the exchange, the value of token will increase, and the price of XCP is finally determined by how many users and how many funds will go into the exchange.