Yup, it works fine. The .30 can is more expensive, so there's a financial reason to stick with your needs at the time. But then again, if you later decide to get a .30 can, you get to go through the entire fun again.
The volume of the .30 is going to be larger, so in theory it will help quiet it a bit more. It's going to be larger and heavier though, so if you're thinking about weight being an issue there's a reason to go with the smaller one.
I decided to go with a .223 can instead of a .30, but I wonder if maybe that wasn't the wrong move. Another couple or three hundred bucks and I'd have had a much nicer .30 can that couple be used with a .300 BLK or .308 rifle.