You can get Quad actives on the grey market here within that price range. Don't know if that is also true in Europe. The 11Ls would probably boot the A5s sound wise, but are also a lot more fiddly/tweaky for good or ill.
Got my Myers-Briggs analysis back. I am (still) an INTJ and my marked propensities are for tenderness and procrastination. So I guess if you ever need someone to promise to hold you and then never get around to it, I'm your man.
Also made Irish stew, which I'm now eating.
I bought my friend some Yuin OK2s for his birthday to use on the train. He's very happy with them and I thought they sounded good when I listened to them out of my iPhone for an hour or so after they arrived.
But at that price point ($170), I'd personally look for some used X10s. They're just killer out of a good amp.
I agree that the GS-1 does a very good job with Senns, but think it's at its best with Grados. My impression is the reverse is true of the Zana. Solution -- run both.