Seems like the DoS prevention code in GLD prevents people from hopping on when it comes to the top of the profit list.
The defense protects the network by preventing hashpower from being added to quickly.
It basically gives more power to the little guy by removing the advantage of someone using an industrial strength mining rig jumping on the network for some quick and easy coins. Mining goldcoin is no longer an exercise in raw hashing power.
Akumaburn wrote about this is detail yesterday:
https://www.gldtalk.org/index.php?topic=1262.msg6081#msg6081 It is not working, I do believe you broke it. I mine Gold coin from time to time but cannot even find a block that does not orphan at this point, even though I found several today. This might protect it from the multi-pool but it also stops the people who are serious about it. Major problem in my opinion.
It also seems to support single-pool mining aka 100% attack. Bringing online 5.1% to support? Screwed. Bringing on 51% to attack? Harder. Joining the existing 99%? Win.