I actually have quite the collection of Marlin lever guns. Most are vintage with cut rifling. The 44 mag is the only one that I have with the micro-groove. I bought it under the advice of some friends who insisted that the micro-groove was very accurate with jacketed bullets and hard cast. I have fired every ammo under the sun including jacketed of every weight, hard cast, slightly oversized cast, gas checks, blah, blah, blah. I've meticulously cleaned it and begun again. My very best results have been unable to keep 5 rounds on a standard issue paper plate at 100 yards, and I'm a pretty decent shot. I do not have this issue with any other rifle. I can confidently say that my particular Marlin 44 is not an accurate rifle. So, I was looking to replace it with something in the same niche. Recently I have begun to consider rebarreling it with a cut rifling barrel.
Although I agree with CraigC that the Henry is "butt ugly", I developed a passing interest when I picked one up at a gun shop and found the action to be as slick as snot. I don't like the loading technique or the look of the brass. I wish they had a loading gate and steel receiver. I was just wondering if anyone had any experience with them that might sway me as yet I am undecided.
On a side note, Henry sent me an email today saying that the brass receivers are freeze treated giving them the same tensil strength as steel.