MSC tx is considered as spam. I am wondering if XCP have the same issue?
Yes, XCP is
blocked explicitly.
As well as
all m-of-n transactions are
blocked in general (which are 85 % metacoin transactions) on Eligius.
Furthermore:
SatoshiDice, BetCoin Dice, 1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T ("correct horse battery staple"), SatoshiBones and Lucky Bit.
And transactions trying to spend coins received by blacklisted output.