My (purely egoistic) point is, that I'd rather have the Junkers G.31 than the W.33, for the simple reason, that the G.31 is the largest gap in my
collection of Junkers planes - as I said: Purely egoistic!
F13s are a bit... hmm... grey, but at least the Eurasia planes were a bit more colorful.
The the
Colombian SCADTA operated a fleet of float F13.
And, finally, I've found
one single picture of a F13 with an enclosed cockpit, I think there were next to none such planes (but at least
one).