20mm f2.8D as lightweight D800 companion

I hear only good things about this lens

I am assembling a lightweight "travel kit" for a D800E.
Backed up by Thom Hogans (:)) latest article ....
I was thinking of the new 28mm f1.8G, 50mm f1.8G and 85mm f1.8G

However I would like wider, and would tend to do landscape and architectural pictures between f5.6 and f11, so the 20mm f2.8D might be a better choice then the new (untested - but surely good 28mm) as it gives me a wider perspective

any views on this substitution ?

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http://www.haroldmiller.me