Of course I realize that neither are really unlimited. But like I said 10-15 TB should be more than enough. I actually don't expect to cross the 10 TB mark any time soon (definitely not within the next few years).
I noticed about Jottacloud's speed throttling, that actually doesn't seem too problematic for my case. As for OpenDrive, do they actually kick people out that have like 10 TB stored? (which I won't have initially, but may get there eventually).
Thanks to everyone for their comments. I actually ended up with Pcloud: I took today's Black Friday offer of 10 TB storage for a one time lifetime fee of €890. Unless they go out of business, I expect this will suffice for my needs indefinitely.