Dear 7 Mag,
Your answer is totally on the money. There is no reason to get a 6.5 Mag, even if you really want one. It is a failed and obsolete cartridge, that was a total failure from the beginning and remains one to this day. Recoil and muzzle blast were very bad, and it burned up barrels. From the time they were first brought out, everyone realized you just didn't need one.
For purposes of hunting on the lighter side of the 7 Mag, I think that the new 25 WSSM, or the 260 Remington would fill any need. If a magnum is really desired, then the .257 Weatherby Magnum is a tremendous round, and was one Roy Weatherby's favorites.
As far as being a deer slayer, the 6.5 Remington Mag does not drop them any harder or cleaner than a .308 Winchester, the .270, the .280, the 7 mag, the 6.5 Swede, or any of a group of 20 other rounds. You can only kill a deer so dead.
Just my opinions.
Big Paulie