Is it normal for shares to drop, drastically, when swapping to mine on a p2p pool? I've not tried it before, so it's still a new experience to me.

I'm using their suggested cgminer string, from their site:
usage: cgminer --scrypt -o http://p2pool-dgc.com:9500 -u YOURDGCADDRESS+0.0025 -p x --queue 0 (and a bunch of other stuff for my 7970s)

I understand the +0.0025 states some sort of local difficulty?