Good service, but for my small rig 3,8mh, too big sharedificulty 512, i lost share at fastcoin with small dificulty.
I thought the same but have a read through this -
https://bitcointalk.org/index.php?topic=279644 - it explains the share difficulty not actually being that much of a problem as long as you mine for an extended period of time and not just a day or two.