We'll be covering it with metal.
I hear what you are saying about the loft space being much more limited on a monitor barn, and for me the trade off is something that I considered for a long time before deciding that a monitor barn is indeed what we want.
This barn is very visible from the front. We can see it from almost everywhere and it was important to us that it looks good and is pleasing to the eye from all angles. Trish loves the monitor barn look.
I might have been happy with a full rounded-top type barn like I knew when I was a child in Wisconsin, but the monitor barn is more common out west for some reason and it's the look that Trish likes.
Also, the loft is 12' wide by 36' long which is 432 square feet, with about 7 feet of head room. I figure I can store as much hay as we're going to need up there.
Lastly, we're putting some windows up there on the side walls in the loft, and that'll let in a lot of natural light.