I take the contrasting view (vastly prefer Enterprise Linux) but write software that has to support many distributions.
Generally speaking, there are better package review standards applied to Fedora (Red Hat and CentOS upstream) and you don't have things like debconf that make figuring out how to do a non-interactive install a little confusing.
This means that in general there is less "randomness" that will occur than in your typical apt package.
Kickstart is also easier for users to bootstrap installations than preseed files, which in many cases require scripts to all be written on a single line. Writing preseed files causes me immense pain.
.rpmnew is also a nice system for replacing configuration files. By contrast, I've had apt purge fail when files were deleted prior to running the purge.
Ultimately I'm not sure what kind of repositories you are working with, but that may be the problem.
I would choose CentOS or RHEL every time.
Many slowness issues can be solved by maintaining a local mirror and also by disabling the fastestmirror plugin -- while perhaps good for slow connections, the mirror speed checks cause added delays.