Concerning the API - pCloud does webDAV which works well enough. Any reason for mentioning/requesting about using API approach?
From my speed testing - Jottacloud and hubiC were both really slow (Jotta cripplingly so and hubiC not amazingly better). Talking about 10-15 minute backup times on occasions on a 10mB - I shudder to think what a large (multiple hundred Gb or several Tb) would be like on those platforms
(hmm… maybe another test suite for me… but that would take much much longer to get results)