I would like to add to what Steve is saying based on my personal experience.
I have a Marlin 336 in 30-30 that is pretty accurate ---if and only if I put one or at most two rounds in the rifle.
A tubular magazine loaded full is just not very accurate as it changes the barrel harmonics with each round shot. That means that the 1st round, 3rd round and 5th round go in slightly different places on the target.
This is why I limit my Marlin to one round in the chamber and one in the tubular magazine. If I so limit myself, then I can load just about any pointed ammo I want in my Marlin and have every advantage of the Leverevolution at much less cost. and no real risk with the right loading procedure.
If I am really paranoid, I could put in a magazine plug like my shotguns have, to make sure I never have more than one round in the magazine.
If I want to shoot farther out that 100 yards with my 30-30, then I want the accuracy associated with a limited amount of ammo in the tubular magazine. If I want the downrange performance of the Leverevolution, then I also want the long range accuracy as high velocity misses don't do much.
Therefore, as Steve says this is a gimmick to handloaders. To non-handloaders, it is a reasonable compromise considering that in the litigation prone society a manufacturer probably can't safely sell 30-30 rounds with sharply pointed bullets, unless they are soft like the Hornady rounds.
It is an interesting concept, but more hype than reality for handloaders.