Stats are mailed once a month and a poor guy called Rich is in sole charge of the aff program so expect delays to email enquiries. 
We find they convert decently, the stats track very well, payments may be delayed a bit but they are on the up and up.
Party Poker, there is no comparison as they are the CON of the poker world. We probably make 4x at Party than at Stars.
Hope it is of some help.