Göran, I've been evaluating Glyphs 2.0 lately (and the beta some before that), and I'm very pleasantly surprised. I said three years ago that I was going to try both RoboFont and Glyphs, but I was so taken with RoboFont that I never got around to giving Glyphs a serious try. Now I have, and, although I'm not going to abandon RoboFont and my other UFO-based tools (they can do a lot of useful and amazing things), I will probably switch to Glyphs as my main production tool.
The built-in TTF hinting was one of the things that got my attention because, until now, none of the TTF hinting workflows that I've seen was very practical to me, mainly because the TTF hinting was towards the end of the production process and necessitated forking my font data into separate OTF and TTF production files at some point. I really hate having multiple sets of source files. Glyphs lets you do the TTF hinting very early in the design on the interpolation masters and before removing overlaps! This is huge, because it means means the hinting becomes part of the design process, and the burden of manual hinting (when it is necessary) becomes much more manageable. (It's very much in line with what Petr van Blokland spoke about three years ago at Robothon.)
So far, I am pleased with the hinting results I'm getting on Windows. Testing does require moving the TTFs to a Windows machine (VMWare in my case), but it only takes a few seconds to see a preview for each new itteration.
Aside from that, Glyphs 2.0 has other advantages that are making me take it seriously:
Much smaller, fewer, and more manageable data files which means it will be practical to use it with things like Dropbox. (Example: 24 font family: 6 interpolation master UFOs + 24 instance UFO files totaling 160MB vs 1 Glyphs file totaling 2.5MB, plus each UFO is actually a folder containing hundreds or thousands of .glif files)
More focussed and integrated UI
A much simpler workflow than anything else I've used, which lets me focus on design
Although it's not as seamlessly integrated as it is with RoboFont, I can still do my kerning in MetricsMachine
It does have it's quirks and annoyances, but I'm very impressed.