I just picked up my new Trucker yesterday and am finalizing the last of my accessories, including shoes. I've decided on Shimano M324 pedals because this will be a touring/communiting/town bike and I want the flexibility to use regular shoes (for farmers market/coffee runs) as well as SPDs (for touring and commuting).

I tried on all the MTB style shoes my LBS had in stock in my size and didn't like either the comfort or sole stiffness of them. They mostly had Bontrager and Giro shoes. At the end, though, I tried on the Sidi Dominator 5, which was supremely comfy and stiff, but I'm right in between sizes and don't want to buy them if they'll be wrong (I can't return them once I install cleats). I'm a US 13 and right in between a 47 and 48 in the Sidis, and they don't make a 47.5 (curses! they make half sizes to 46.5). The LBS staff suggested adding an insole to the 48s might help.

Does anyone have experience taking a little volume out of shoes with an insole? The width is fine, the 47's are too snug in length and the 48's are slightly long.

Alternatively, what other MTB shoes do you have experience with? I'll probably have to drive around to a bunch of bike shops to try 'em all on, but that's ok.

I have Specialized shoes, in a 48, for my road bike, they're just a smidge long too, and I notice my foot shuffling back and forth a little, which isn't too comfy.

I've used both Shimano and Specialized MTB shoes. They're both a better match for my foot than Sidi seems to be. Currently using Shimano MT-31 "mountain touring" shoes for around town/commuter use and Specialized BG Comp for off-road and long-distance rides.

I would go for the larger shoes because you can adjust to fit them - insoles, thicker socks, feet swell on a long ride...
The small shoes will always be small.
Unless of course that the large shoes are too large, even with insoles. I still wouldn't buy the small shoes.
I'd look for other brands and models at different bike shops.

My Sidi Giau 45.5 shoes were a little too big and the next size down felt too small. I dialed them in with some thick thorlo socks. It worked perfectly.

I use other, more supportive insoles in my shoes, than what came with the shoes,
a lot..

I wear 13 and find the Sette 47 shoes are a really good fit, not short, long, wide or narrow, however I have flattish feet and find most shoes have too much volume top to bottom so I use Superfeet insoles, the thickest green or orange ones, which are expensive but worth the money if you can get them 20 percent off or on sale at REI. I get the size 13.5 to 15 Superfeet because I like the larger arch/prosthetic insert and cut the toe area and width down to fit. In winter I replace the green or orange insert with thinner blue ones to create room for thick socks.

Small shoes will always be small- this is key!
I made this mistake once, I would highly recommend not doing it.

Trying on as many diff models and brands is great for you and your feet to figure out what feels right.

Good luck