I think the trapper style carbine feels absolutely the best in hand. I do prefer the pistol grip configuration, more than the straight stock, and I believe the new Ruger/Marlins are some of the best made marlins. But many calibers were never made, and I love having a lever gun to match my revolvers, so part of my quest is getting the calibers I want, custom made.
I currently have a 45/70 marlin 1895 trapper (was NIB) waiting on barrel work, to be configured into 475/70, which is just a straight blown out 45/70 case, into 475 caliber. It doesn't gain really anything over a 45/70 cartridge, in that configuration, except now it will cycle and shoot 475 Linebaugh Maximums. Which is the point! I have a converted Browning M71 High Grade, with 16.5 barrel in 50Alaskan, that cycles and shoots 500 Linebaugh Maximums flawlessly.
My (longer barrel, 20") Marlin 1895 from WWG, with the beautifully thinned and lightweight Kevlar stock, cycles the 500 maxi perfectly as well, but it's too long for this conversation.
The absolutely "one of a kind", 500 Linebaugh, built by John himself, which we agreed it is named "The Reason" as it is the Reason John never built another one! It is an 1895 Marlin, with a turned down 50 BMG barrel but timed to shoot 500 Linebaugh, although you can single feed maximums. It was originally a 22” barrel, now resides at 16.5”. John Approved, although he wouldn’t “That Da** Thing” to give me his opinion of the “Trapper” length, but he liked the way it felt handy to him.
The 500S&W BHA is another wonderful shooting gun, and very handy in 16.5".
Although Marlin trappers in 45 Colt are not out yet, I have one on order, so hopefully their "summer" production dates are current.
Still a lever, but not a repeater, I converted a pair of Ruger No1's, with the same 16.5" barrels. The 50-110 is an absolute Beast, but can also fire the shorter 50Alaskan, 500 Max and 500L. The other No1 chambered in 45-90 is an Octagon monster, and although I was planning on a 16.5, came as an 18", and as it balanced so well, it remains "long" …. For now anyway.
The stock Ruger Marlins, SBL (Trapper Lengths, 16.5) both pistol grip, stainless Lsminate are simply a joy to shoot. But there is something about those big straight wall cases that just bring a smile while handling and shooting in a Trapper length lever of any brand!