Again, that's not to say that it's built as large as a full frame, it's clearly, obviously, physically smaller, and thus the gears will be a bit smaller. That said, a ton of guys run mid frame 12k winches with success, hence my recommendation.
Glad you found a bumper to work for your needs.
Its not just the size. The part about it already being in the garage is a big part too. I'm not talking about buying a new M12, rather using the one I already have owned for years. Up until this truck, I've never had a problem finding a good utility bumper to handle these things. If I was buying a new one, yes I'd probably go straight for the 16.5. I may need to go bigger anyways, especially if I ever need it with a full trailer attached.
It's been on multiple trucks for me, and has seen a LOT of use. I've replaced the cable at least 6 times from wear. Then the 125 feet of cable on the drum. I'm losing almost 50 feet on mid frames. Yes, I carry extensions, but it's awfully nice not to have to deal with that 99% of the time.
But then even this Steelcraft turned out to leave out some critical fit information...it's not set up for a foot forward mount, and according to Steelcraft, that's because Warn makes flimsy products. I need to measure the tray again, but I'm not sure it can even accommodate a Superwinch 18K with the 8 bottom mount bolts they use.
It's been a shockingly frustrating process, but then I suppose that should be expected, as 99% of trucks sold to consumers these days are for image to people most concerned with looks, and commercials guys running these big winches are buying new trucks, not building 10 year old trucks.
So maybe I'm buying a new winch at this point anyways....