It must depend which Remus. My brother has a Hexacone with Remus headers. Even without baffle it's really not a noisy pipe. Standard can with Remus header made more noise than the full Remus system.
Another point on noise, my Akra without baffles at 70mph makes less noise than the front tyre. I need ear plugs to cope with the tyre noise so TBH the exhaust is not an issue.