The "Remlins" that I've seen lately seem better in terms of fit and finish... They had a bunch of them at Cabela's in Rogers, AR last time I was there to stock up on fly fishing stuff.
That said, they aren't something I'd trade my c.1975 336 for.
The original North Haven, Ct. Marlin could turn out some substandard stuff, too. I credit them for my ongoing and current reluctance to buy any firearm without seeing it in person and handling it first. I had a dealer order me in a pair of 1894s in .218 back when that version came out. Compared to my mid-seventies 336, both of the guns I received were turds with very obvious flaws. One of them was really bad. I gave my sister the least turdy of the two, having a gunsmith replace the bent front sight, clean the burrs off the lever and re-blue it, and some other thing that I don't presently recall, prior to giving to her. My sister had a happy 16th birthday and was proud of her first gun, and still shoots it today, but if I had the opportunity to see those rifles in person before buying, I wouldn't have bought either one of them. Those shoddy rifles were made under "Kenna Era Marlin's" watch. I haven't seen a "Remlin" yet that was worse in terms of lack of fit, finish, and attention to detail.
If I didn't already have a 336, those new ones I saw last might be tempting, but I wouldn't have the frame of reference that I have through owing mine since I was 11 and shooting the snot out of it for the last 37 years. Because I do have that frame of reference, if I were shopping for a replacement for some reason, I'd be looking for the cleanest old 50's, 60's or 70's 336 I could find.
Your mileage may vary.....