My small stash is mostly old style fuzzi bunz, which I love. The new style has definite improvements, but they do seem to fit larger and there are differences in fit. After finding the new style mediums were much bigger on her than I expected I bought a new style small to compare. The old style is the periwinkle, new style is the bubblegum.
Rise is much higher on new ones
reworked shape
new bigger, softer gussets, very soft

(old is on top)
The size difference is mainly in the legs, so if you have a long skinny baby like me the smalls will likely fit a long time. I like not having to tuck in the long wings. Love the new topstitched front, keeps the top from rolling.
5 pins!

just be aware that FB has not changed the size chart on their site yet... hopefully they will fix this soon.