Some improvements were applied, most noticeable one is: Fair way for paying providers. It does not matter the order your miners work on, your miners are paid average sum, according to how much work (shares) was provided by them each minute.
A welcomed improvement. Now if only something can be done about those pesty rejects. In particular I notice that rejects come in batches and streaks. For example, if the next submitted share is rejected then the probability is high that the next several consecutive shares will also get rejected. It's almost like there's a new block or new work but the server didn't notify the miner in time. This causes higher than desirable reject rates when compared to your classic multipool.
