"Boris Bikes is still the best, but restricted to central London and can't unlock via phone."
Not true! The official Santander Cycles app lets you hire a bike via your phone. Works well and saves a huge amount of time compared to using the kiosks.
I agree that the current Boris Bikes are the best, though they have a new lighter, smaller bike model which feels a lot more like a Mobike/ofo to ride. Not as nice IMO.