Probably can't be defined as a SERIOUS disadvantage, but it's certainly a real phenomenon-- pollution.
No, not like it's going dry up a rain forest or kill off a gaggle of baby eagles or anything, but it's VERY much like that cheap, surplus, lacquered steel-cased chi-com crap 7.62x39, 9mm and Makarov ammo that is absolutely scattered from hell to breakfast on every outdoor range we've ever seen.
Regular old brass gets picked up by the end of every day, or before lunch time the next day.
If you police your own brass, or shoot indoors and the range nazi's steal all of it, obviously not much of an issue.
I tell you what though... it keeps me laying awake at night knowing that you scatter 10mm brass all over the place... even worse if you switch to that cheap old Blazer stuff! I would love to get a hold of all the once-fired 10 brass that you shuck out of your DW and G29.