I'm always for the Metroid Prime approach. Stay faithful to the original, just improve the presentation. That said, Metroid Prime aged very well, so it didn't really need any changes. I'm okay with changing some things if they improve the overall experience without taking away from the original - remasters such as Wind Waker HD or the first Crash Bandicoot in N. Sane Trilogy are good examples of that.

Overall I just kinda hate the idea that there can be two different games, two different works of art essentially, with the same name and premise. This kind of remake happens a lot in movies and I always disliked it, so I'm not a fan of it now being done in games. Like if I were to play Resident Evil 4, I'd love to play a new remake that looks and sounds way better than the original - but then, it's not the original, so I'll end up feeling like I didn't play the "real" Resident Evil 4. And if I want to play the real one, I'm stuck to more outdated presentation and can't do it on a current platform.

edit: Also, with the amount of effort that goes into making these types of remakes, I'd rather they just put that on making something new instead of making a different take on something we already have.

Ok, I see how you could have interpreted that as an expectation, but that's not how I was trying to use the word should. I was using it more as a suggestion. For example, if I say to someone at a restaurant, you should order the ribs, I am not saying that I necessarily expect them to do so, just that I think that would be the best course of action.

Nintendo was pretty clear on what Metroid Prime Remastered would be, so I have no issue with them releasing it, and no issue with anyone who thinks they would enjoy that experience buying it. Just not what I would prefer.

If the only change is upgraded graphics I see no reason to buy the new game if i still have the original. I rather have multiple different experience with the same core, than the same experience with better paint job.