This is why MIddlecoin is better in this part, I wouldnt be surprised if this is the reason middlecoin is what it is and the way it is, without a front.. I am betting it would be more complicated to hack Middlecoin.... I mean how would a hacker change the payout addresses there, we all have our workers usernames as our BTC wallet addresses. I think this is one of the reasons middlecoin is what it is. The less there is up front the less there is for people to hack with.
There certainly are advantages to Middlecoin's method of operation.
That said, there are also advantages to Hashcows' method of operation. Some people, including myself, believe that VARDIFF is beneficial for low-performance machines. Additionally, Hashcows allows me to choose to keep altcoins at my discretion (even though I don't) and importantly can provide statistics for each machine, allowing at a glance to see how all my machines are doing, and breaking down rejected shares by machine, allowing troubleshooting and tweaking. Hashcows also allows a low-performance miner to take payouts every couple days or week (or longer, if you're stupid) to reduce the amount of dustiness in their wallet.