I've been merge-mining at p2pool.vtcpool.co.uk for ~15 hours with an average of 900kh/s. My only payout was 0.06VTC around noon.
I should have gotten around 2VTC and (a guess, i have no idea what the block reward for mon is/was) 1+ mon..
It is delayd by many hours, up to 24h before you see expected payout amounts. It's like that on all p2p merge mining pools. And with defaults you need 1 MON or 0.1 VTC to get paid.
So the worst thing you can do after hours of mining is jump to an other pool because then it will be waisted shares.