I've got both, live & hunt in Florida, similar terrain (swamps & brushy country).
I like the easier-to-handle recoil of the 1951 Marlin 336 in .30-30, and I love the thought of carrying a rifle that a grandpa used.
I also love using the 2008 Marlin 1895SBL in .45/70, it is a one-shot-stopper.
You hit a Hog with it, or a deer, they just fall over DRT. Gotta luv that
Lately, I prefer the 336, mostly for the Down Home feel...and I tend to take a little more care in shot placement with it...
where with the .45/70, I just quick-aim for the heart thru the Ghost-ring sights, and if it gets moderately close, it drops 'em.
And there is a certain Tim Allen More Power feel to the newer .45/70
Gets the caveman in ya fired up!!
But I just keep reaching for that old 1951 Marlin 336...one of these days I'll slap a tang sight on it...
but for now, its running just as it came from the factory back in the old days.