I'm just a casual user, and I didn't really notice any difference between deb and rpm. But I did notice a significant difference between apt and yum. Yum was much slower and less clever in figuring out dependencies. I've had yum uninstall unrelated programs sharing libs with the one being uninstalled. It seems like apt(itude) has more advanced resolution algos built in. Plus more is avail as deb than rpm, no need for manual download via websites.