I haven't tried oBike as I am already customer of two other bike rental schemes in my town (Munich) but from what I see when looking at those and from reports they are really bad in quality and comfort.

As an example here a (German) video comparing oBike and a "normal" bike rolling down a small hill: https://youtu.be/9bTnwJc5gzc

There are probably better ways to spend those bucks.