The only way (as KmH might have discovered) for these services to work to satisfaction is if you have a fast connection upstream. That type of connection is going to cost you.
I use backblaze and have been happy with it. I haven't needed it yet but I've tested retrieving files it and it worked fine. Probably took 3-4 weeks to upload everything (100gb to start with I think over a ~10mbps connection) and now I just back it up after I load new pictures. It's always done by morning when I backup over night. Definitely good for piece of mind. Got a call that my house had been broken into a month ago and didn't know if my laptop was gone or not. Turned out they didn't take it but I at least knew my pictures weren't gone even if they had.