I personally like the older Marlins and I own three.
A .30-30 that I stole from a local FFL about 15 years ago, a 39-A Mountie, and a .35 Remington that I bought from a neighbor a few years back.
The Micro-Groove rifling to me, is no joke and with reloads, the rifles are capable of super accuracy.
My 39-A is a well cared for rifle built in the early 60's and I installed a vintage era 6X Weaver scope.
The .22 of course shoots some ammo better than others but the rifle is by all accounts, GREAT!
IMHO, you cannot go wrong with an older Marlin rifle .
Stick with the 336 though.