I love Metal Gear Solid 3: Snake Eater. I love playing the game, hanging out with other people while they're playing the game, reading about the game, and watching videos of the game; you name it, I love it. It would have been really hard for Konami to make it so I don't enjoy playing one of my favorite games ever on my current favorite videogame console (the 3DS), but heavens to Murgatroyd, they came pretty close.
Metal Gear Solid: Snake Eater 3D does not come off like the paragon of technical excellence that the original title did when it was first released on the PS2 in 2004. Part of that is because the 3DS is not a PS2. Nintendo's latest portable is capable of much more than that now-"retro" home console, as proven by titles like Resident Evil: Revelations. The other part is that Snake Eater 3D feels unfinished. There are a few cool new features here, but Snake Eater 3D is also a downgrade from the original in a lot of ways -- not something you'd expect on newer hardware.
It'll be up to the individual consumer to determine if Metal Gear Solid 3D: Snake Eater's technical failings are damaging enough to cancel out the worth of the port's newly implemented features, and the original title's impeccable writing, scenario design, and gameplay design. Maybe you'll have a better time of reasoning that out for yourself after I break down some details for you.