DL doesn't charge separate admission for Christmas festivities.
There's less at DL to see and do in terms of entertainment BUT (in my opinion, as well as the opinions of my family) the Christmas Fantasy Parade at DL is way better than WDW's Christmas Parade.
Believe in Holiday Magic is also a spectacular fireworks show(the only one better is RDCT, Illuminations is 3rd in my book), and as a prior poster mentioned, you don't pay extra to see A Christmas Fantasy and Believe in Holiday Magic. Plus, Disneyland has a holiday layover for Small World and Haunted Mansion whereas WDW does not. It may not have a Christmas party, but the lack thereof does not diminish Disneyland's Christmas offerings.