Here's what I do, I shrink a partition on my HDD (or have it already partitioned so theres space for several OS partitions, Then I install the latest and great

Here's what I do, I shrink a partition on my HDD (or have it already partitioned so theres space for several OS partitions, Then I install the latest and greatest on the free space or a much older distro partition, leaving my current work distro safe on its own partition, Next I copy over as much of the contents my current home folder as I can. Now, I can truly "taste" the new distro and if it isn't a good transition I just go back to my current favorite. I've found I probably install a new favorite distro twice, first time is to check it out, mess with stuff decide if its an improvement or not, and ensure everything still works. Then re-install the second time, now knowing what I like from the new one and just install with the packages/settings that work. Any time I get stuck or have some unexpected difficulty I still have the previous favorite distro to boot back to in an emergency.