swap file vs swap partition have pros and cons. Some capabilities that swap partitions support are not supported by swap files. I suspect it is just because they are so new that all the different uses for swap haven't been fully fleshed out and some failure scenarios still exist.

OTOH, if still using MSDOS partitioning in a dual-boot setup, the limited number of primary partitions (4) can make having a swap partition troublesome or impossible to setup.

I'm so used to allocating storage assuming swap is outside the / partition, so wasting 4+G of storage for swap really isn't in my planning.