I run Plex on my home server to host streaming for my media, and also run a separate VM on the same server strictly for torrents (dl/ul). Issues I've run into using cloud storage for Plex are: 1) space (I have a LOT of data and it doesn't fit without paying for add'l space); 2) speed (spinning up a stream is slower over the cloud that hosting in-house).
Plex is cool in that your stuff is always accessible from anywhere, regardless of where the media bits are stored. I actually store mine on a 4TB USB3 drive connected to the server. The server has a Samsung 1TB SSD which would be even faster, but those bits are costly compared to the USB drive. I also have a second 4TB USB3 drive mirroring the first for backup.
When in doubt, I always prefer the in-house, owned-hardware option given that most internet speeds these days are more than sufficient to host and stream via Plex, in addition to ul'ing/dl'ing torrents at the same time. Up-front cost is high--depending on the setup--but there is ZERO recurring cost and you control 100% of everything. There is something to be said for that. Have never run into an issue yet where my own h/w or bandwidth has been the bottleneck.
