I use a steel one with a proper screw in plug (not those silly push button things. What happens when the internal plastic mechanism breaks?).
It works fine up to FL080 although the pressure equalisation is noticeable when I first unscrew the plug.
I'd expect it would be fine in a pressurised environment. To guard against depress. problems you could unscrew the plug slightly. The cup/lid doesn't seal very well but helps control accidental spills.