gmb_uk
You're incorrect about that, but the MAAS team did suffer some short staffing last year that left us behind the curve. We've now increased the number of people working on MAAS, which is what allowed us to get large chunks of work – like integrating CloudBase's work for allowing MAAS to provision Windows machines – relatively quickly.
Truth is that the problems that MAAS is trying to solve are hard, and it's taken us some time to solve them. We're spending a lot of time in this development cycle working on the robustness of the MAAS node lifecycle.
MAAS 1.5 is significantly better than 1.3, and getting stronger all the time. Similarly, Juju 1.18 and 1.19 are leaps ahead of 1.13 – the local provider is now in a workable state and gets used a lot internally.
We at Canonical eat our own dogfood as far as MAAS and Juju are concerned. We're using MAAS extensively in our DCs (though I don't think we use it for 100% of machines; I'm not privy to that knowledge) and the vast majority of our core services are deployed using Juju.