I go with mono because most music sets I record don't extend over the file size limit that would cause an automatic track split. It's not a really big deal either way though. I do think that if I was recording in 24/96 or 24/192 and 4 or more channels, I'd trend towards using mono files because it can get a bit tedious piecing together more and more pieces, because the length of each piece would be progressively shorter and shorter as you cram more channels or bits into each 2GB file.
One reminder that if you do go with mono files, in post you need to pan each of the channels either 100% to the L or 100% to the R when create your stereo mixdown file. Perhaps this should be obvious, but it wasn't to me when I first started using mono files. Since I didn't manually pan my files, by default Audition mixed the combined two channel file to mono which was confusing to me for awhile until I realized why. At first, and actually for a few days afterwards, I thought that I'd set up my recorder wrong and that I'd eff'ed up the capture, but then I figured out that I hadn't done the mixdown right.