I'm not sure but it might be that Fedora is faster. at least my Arch is a lot faster than any RH I used to use, or any other distro I've tried out
and yes, you can keep your /home directory as it is. just do this: when installing the new distro, be careful on the partitioning part - I'm not sure whether you have to do it manually or not to get this work (I have never done it automatically), but I'd say you can do it manually since you already have a linux partitioning on disk - so choose manual partitioning, keep current settings, and check every step for an option to format the partitions! on some screen there surely is (I haven't used Fedora, but in every other distro there has been the possibility) an option that asks you to choose if you want to format or not the partition(s). choose NOT to format the partition your /home is in. this way nothing gets overwritten and your /home stays as it is.
you can, of course, make a backup of it to some cd-r(w) but I'd say it's quite useless. if you cannot find the option and are unsure if your /home gets formatted, just don't save the partition table or go on with the setup before you have found it (or quit the setup).
but I guess there's a 99% chance you have just missed the box until now - it is there