I'd jumped on Koding.io when it started and was giving out some 5 GB for referrals. Soon the initial enthusiasm faded when the VM was not reliable, would switch off while programming and generally be ultra slow.
Checked back again after seeing your post. It still seems buggy (billing options won't show up, PATH variables not being set for some new packages to name a few). Haven't tried the other two you mentioned.
And if you are using containers, whether you use Ubuntu or Mac, there is hardly any difference. Only thing you might be sacrificing is the ability of being able to use any machine with a browser to do your work.
Also many of us work with other desktop software like Photoshop, Illustrator etc during our development process which might be a pain to sync with the VMs during testing.
But you have me interested in cloud IDEs again. Have you faced any issues using c9.io? Would you recommend a complete switch to a cloud IDE?