I built mine without carpet. It has barberpole vinyl over the rockers and firewall, nothing on the floor under the seats and a wood "floating floor" ahead of the bulkhead with a rubber mat fixed.
The vinyl bits can come out and go back in with little trouble: they're velcro'd. It all looks exactly like it should.
That said, carpeting has got to be better for real-world livability. It's sound-deadening and renders acres of troublesome interior panels good looking without resort to paint or aluminum and rivets (or both, as I did). Simpler, cheaper, arguably "better" because, comes down to it, who are you trying to fool?