I had shockingly bad experiences with OBike - extremely inaccurate locations for their bikes, broken seat, zero response from support when I explained I couldn't lock the bike, and apparently no restrictions in the whole country, so bikes end up all over the country as well as in people's residences or workplaces (not to mention canals and rivers). They dumped hundreds of bikes in central London and a couple weeks later there were none at all.
Mobike seems like they have their heads more switched on, but the seat on current models is so low that their bikes (in London at least) are barely usable to anyone at average adult height or above.
The official London scheme aka Boris Bikes is still the best, but restricted to central London. The docks have three downsides over the newer model - (1) docks can get full and (2) you still have the last-mile problem walking to/from the dock (3) if unfamiliar with your destination, your ride ends hunting around for a dock to park in or you have to plan ahead and remember where to park ... even then it might be full.
One good thing though is they apparently move bikes around in vans to help fill capacity (mainly because commuters move them central in the morning and away again at night). I don't think the new wave of bike startups expanding to new cities every week are hiring drivers to move their stock around.