Most people saying the original is better are saying so from nostalgia. There are some strange changes to Twin Snakes such as the cutscenes being weirdly over the top anime shit, which are definitely weird decisions and a downside, but if you hold no affection for the original it's not a big enough negative to be a real problem. For controls and graphics alone, however, Twin Snakes blows the blurry, D-pad controlled, fuck ugly original out of the water. The PS1 version of the most dated looking and playing games I've played in fact. Aiming some of the weapons with the D-Pad is outright comically bad. The story is the same in both, so it depends what's more important to you, playing the classic original that made people love the game, or a more modern, nicer looking, much better controlling version.