Yesterday we shipped version 3 of our CMS products Perch and Runway. The big news there was the redesigned UI, which uses a lot of Flexbox - but still has to work in whatever old browser people are using to manage their site. Had we started this now I would have used Grid for some elements, and there are likely to be enhancements to what is there using grid over the coming months.
What working on the U really showed however is how well our new layout methods work with the fallbacks. It was very easy to override
display: table to turn items into flex items - I just wish that those old browsers supported feature queries!
No rest for me post launch as I am heading to Oxford for Render tomorrow, then onto Seattle for An Event Apart and San Francisco for Smashing Conf. Come and say hello if you are at any of these events!