Wow, I loved what I've seen so far, I can not wait to play your game.
Because the PSX style is inconsistent as fuck and never really figures out what it wants to be, therefore I have no real consistent basis to go by in regards to emulating it. Seriously. Look at X, then at General, then at Eregion, then at Final X4 Sigma, then at Hell Sigma, then at Nightmare Mother, then at Blizzard Wolfang, then at the X4 stage select, then at Gamma Sigma, and then at the D-1000. Then try to find a consistent style. Trick question, you can't.
It's also rather ugly and overly shine-heavy and I really don't like it.
SNES style is much cleaner and gives me far more options for striking visual design that doesn't require whoring solid-white highlights on everything.
Great choice by preferring the SNES style, I fully agree with your point of view. Old graphic limitations, such as the 8-Bit NES for example, forced artists to produce more "iconic" graphics. A dirt floor, or metal, does not have to be realistic, as long as you get a quick and clear idea of what it's about. The SNES was the pinnacle of this kind of ghaphism for the Megaman series, with fewer restrictions, but still forcing artists to give personality to graphics. From the 4th game onwards the "need" for pre-rendered and more "realistic" graphics made everything more gray and without personality.