Actually yes, for a few days before I switched to the 3x1 setup, I had one of the monitors setup in portrait. It didn't really end up working for me. On top of being unbelievably tall (a 27" monitor in portrait REALLY sticks up there), it just sort of felt out of place and none of my applications really worked well on it.
Turns out I just really value that horizontal real estate a bit more than vertical. I'm sure if I'd used it for a few weeks I might have become accustomed to it, but it didn't feel like I was getting any value out of it. If it was a smaller monitor, maybe like a 1920 x 1080 or something, maybe that would have been better suited for it?