"ChairMan" was heard to mutter:
i have a 16x20 with the same hinge setup and had no issues
for 20+ yrs. I'd go with the piano hinge again

I think a handful of people suggested piano hinges but most others
recommended bolting in hinges saying it would work better and last
longer. Since we've had to move the exsisting hinges three times to
keep the doors on, I'm not sure how well that would work on this shed.
`Casper

I have not really been keeping up with this thread so if my contribution is
out of order, then I apologize. I built a 16x20 shed 20 years ago. The
front door is a 4x8 door that I framed with 2x3 with a cross X and sheeted
with 7/16 OSB. Hung it with two 3" hinges. I'm in central NY and this
configuration has shown no signs of weakening or failure over all those
years.
Mike Marlow

That's pretty similar to my build. It was a 10x16 kit from 84 Lumber a
couple decades ago. I did a thorough prep/paint job on it initially
and have yet to need to do a recoat. Only problem has been the dang
doors. Almost bought a double-door steel and framed kit from Menard's
to hang in place but it's triple what I'd pay ro repair using same
material and has a minimum six week order waiting period. I waited
last year and they were continually delayed so I canceled till this
year and then other stuff got in the way before I could get to work on
it. So, here I sit pondering my options. I hope to get it done before
the end of the month.
`Casper

PS ... I do appreciate the input from everyone. I do prefer to check
all my options before making a final decision and commecning on a
project. So thanks to everyone.