Swap files are also much easier to set up than partitions if you're using full disk encryption.
How so? It's a one time setup procedure of only a few steps to create a tiny "protective" ext4 (or whatever) partition at the front. Thereafter you configure crypttab to mount the partition via UUID with an offset and key. If you don't need to hibernate you can read the key from /dev/urandom.
Swap files are very fragile if you are using hibernation. For FDE I prefer LVM-over-LUKS and a dedicate partition