All depends on your own personal preference. I have deleted the backbox and I enjoy it. Sure it's loud and on the motorway it can drone, but then I just turn the music up a little louder.
The fun is when you really nail the loud pedal and you get the noise, then the pops and bangs on lift off. Tunnels are awesome!! Plus you have the m54 engine, backbox delete sounds better on that (again.....personal preference)