It’s not about the space used on your PC, that’s just a flee bite nowadays, and if it works offline, its all about the experience and where you want to go.
Depending on where you are coming from, beginner, intermediate or pro(Commercial) Mbed offers different options.
Beginner, the on-line compiler is sooooo easy to use and is pretty quick to compile, I use it all the time if I need a ‘rapid’ solution and sooner get a beer rather than spend hours tweaking an off line compiler.
Intermediate, that’s where the problem starts, you want to do more but the on-line compiler can not give you control on what you need to do, for instance, clock set up options, much like we could do with Mbed-dev. Mbed Studio gives you more flexibility to do some of these, but not enough and no small 32K or less flash support.
Pro, well lets be honest if you really and I mean REALLY do know what you are doing then the only option is to bite the bullet and and get a Keil licence. There are simply too many target’s supported on Mbed OS5 to be a reliable option for professional use, but still great to start out with.
(CLI, who uses that?? and why? command line program or its correct name DOS died in the early eighties. Nothing to do with particular post subject, but I do wonder why.)
Mbed Studio does give you a good off-line solution where you can tweak things but you must understand there is a commercial limit to consider. ARM will want to sell you a Keil licence and rightly so, would you work for nothing?
However I believe ARM should have a more balanced and affordable pricing structure to suit a wider range of customers.