A glass carrier is great but you have more surfaces to dust.
DIGITAL IS FOR THOSE AFRAID OF THE DARK.
I've used my Beseler 4X5 glass carrier on occasion for MF negs and it works fine, although I have the 645, 6X7, and 6X6 glassless carriers for normal use.
I have sometimes shot a piece of sheet film with a 6X12 format in mind, and then simply masked the 4X5 carrier to crop the sheet to the correct size.
While glass carriers can give problems with dust, I solved it for myself with one of the Kinetronic brushes that have the static-less bristles. Easy and cheap.