Then are you sure you aren't just finding fault with the armor design by projecting it into your current perception of Halo? Like, if you reacclimated to Halo 1 by playing it a whole bunch, would you still take issue with it? (Assuming that you don't still regularly rock your original game disc.)
Yes, i find the armor design silly even when replaying the game. Sure, it fits Halo's aesthetic, but it doesn't stop the armor feeling silly, unfunctional. Halo has this "comicbook"-style, stylized but still realistic to some extent and the armor fits it well but... well, I don't know, i just find the armor kinda silly looking. I don't have issues with other Halo's details.
Well, maybe Reach marine's: Their shoulder armor are a tad bulky and not rounded enough, not seeminly protecting their arms. Basically the same issue as Halo CE marine armor, overbulky armor plates that are not very functional.
BTW, I never had the game on original Xbox. Got Xbox around Halo 2, and played that (without Live, local play was fun enough). Have had Halo PC since its release though. Also CEA on 360.
Other than finding Halo CE's gameplay a bit dated, and the fact i know the maps too well (hell, i could draw maps of them probably from my memory, same with Halo 2), and many maps repetitive nature due to lack of visual variety, i don't have any problems with Halo CE single player. Hell, i still feel awe upon seeing some places.