If your working at a larger image size and then reducing it to match the size of the old one then it'll seem that way... if you look at both at 100% the edges would probably look the same.
I've been on and off DA since 2001... watching your work as well as vk, bren, etc... Your use of hard edges and vibrant color is what really caught my eye. A very straight forward and determined style. Brilliant and can't be easy to master.