I lug around an Astron RS-35M. The only reasons I personaly have:
1. I really, really like Astron power supplys.
2. One less thing to load on the 12 vdc house batteries. (it's a 5th wheel, for what that's worth.) When/if we boondock I carry a deep cycle battery just for the radio.
3. Whatever noise the converter makes is not in my radio. There may not even be any noise in the converter for all I know.
4. Got the PS for free. It was in the "obsolete" bin at a place I once worked and I talked them into giving it to me instead of scrapping it. It's just like the one on the home bench. I just leave in the trailer.
I did put a 12v cigarette lighter jack in the bedroom to run a Midland weather radio when not attached to power. Seems the 9v battery inside the radio would die before we reached the next campground...
so I stowed the wall wort PS and did the 12v thing.