I've got a Winchester M12, Ithaca M37, and Browning A5, all in 16 ga.
That group of guns sees a lot of upland duty and performs well. If the selection of ammo locally isn't that great, then use the Internet for a wider selection. Two of mine (the M12 and A5) feature 2 9/16" chambers, so I special order ammo for them. I picked up the M37 so that I'd have one that I could use "store bought" ammo.
One of my goals for this year is to find a decent patterning bismuth load and use the Model 37 for duck hunting in the fall.
All that being said, I don't think there's any great magic about a 16ga. IMO, it shoots 7/8 or an ounce of shot well, and if the frame is scaled right, is a little lighter than a 12ga. Of course, the same can be said of a 20ga, but those tend to be even lighter.
For me, the 16ga provides a bit of nostalgia and is just enough different to be interesting... plus the shells don't rattle around in 12ga-sized shell loops as badly as 20ga. Also, there is often less demand for 16ga guns (especially older short-chambered models), so good deals can be found on the used racks. I picked up my Model 12 and A5 for about 1/2 to 2/3rds of the price that similar 12ga models would have cost.
Unfortunately, this "cost savings" hasn't gone unnoticed and I've watched prices for 16ga models climb rapidly over the past few years.
In any event, you've got a good gun that's a little off the beaten path.
