I tried spider oak a while ago, and I thought it was horrible in terms of ui, performance and bloat.
I'm assuming they didn't change their stack/devs, so I will not even try this one.
I've been using SpiderOak for years without noticing any bloat or performance issues with the background service. On the contrary, I was often surprised how little space I'm using in spite of the fact that they store multiple versions of my files. It doesn't hog memory or bandwidth or CPU at all.
The UI is indeed a bit weird and its performance can be erratic sometimes, but it gets the job done and has a lot of useful features.
Most importantly, SpiderOak has reliably protected me from losing data and I don't have to babysit it. It just works.
(I'm a happy paying customer. No affiliation with them whatsoever)
Then, one day, my account got full, and I couldn't delete anything unless I got some more free space first (see the problem?). I believe support gave me a few extra GB just for the deletion, but that didn't work either and I decided to stop using the whole thing. That's when I switched to attic/borg, which is much superior for my use case (backups).
FYI, the SpiderOakONE app and the backend storage service received a refresh in 2016, and another one is underway right now (now all needed libraries are Python3 compatible!)
The existing UI is oriented toward power users, and is a bit complex for most people. The upcoming refresh simplifies many things while retaining the flexibility under "advanced" settings.
EDIT: I only use the free version though, so maybe the paid plans have better speeds.
Now they also have a galaxy of related products (IM, collab, etc) which more or less integrate with ONE, although I haven't really used them.
No it was actually a couple of years ago, more than 3
I might give it a try.