It don't mean a thing if you ain't got that King....
Hey, my name says it all...couldn't resist....
Check out some Cannonball Adderley discs if you want to hear what
it will sound like (with a Morgan 5M, or Barone vintage "Meyer Killer," of course). That Zephyr from memory would be from around '49 or '50, and very close to the vintage that Adderley was reputed to play, at least in the late 50's/early 60's.
The double-socket crook King's have a huge, warm sound that really has no equal in terms of fullness, save perhaps for the Conn Chu or possibly 10M. They also have a distinctive ring to their tone that few vintage saxes can claim, except for the Selmer Mark VI. Many people mistake this "King ring" for brightness--and in truth the King's may play brighter than some vintage horns--but my current 1956 King Zephyr actually has a rather dark, complex vintage tone, especially when compared to modern horns.
On top of that, if you have decent-sized hands, the key spread on the King's may feel just right to you, and may be the closest to the Selmer feel you can find with a vintage American horn. This may not be as big an issue with an alto, but it is with the tenor. The first time I picked up a Super 20, I remember thinking this really feels good in the hands.
Some people whine about the neck angle on the old King's but again this is more of an issue with tenor players. I personally find it to be ideal. Now the Conn 10M--there's a sax with a horrible neck angle, especially if you're 6'3'' like myself with a fairly long upper body (former high school swimmer here). But I guess people were shorter back then.
Oh BTW the type of resos on a horn make about as much difference to the overall sound as rolled tone holes do--that is, little to none. Volume perhaps, but not sound.
Well, hope that helps. Do you have any pics?