Well, umm, as for lighting, it's 100% shader lighting and there are no lights other than the ones you can see. There is no lighting that does not come from a visible source.
It's compiled with the highest quaity lighting possible.
I don't know how bungie set up their lighting so I did my best to recreate it.
I'm running at 1024*768 with all the settings maxed.
As for the textures, they are Bungie's textures not mine.
They are tiled because if they weren't, it wouldn't look anything like the SP level.
Yeah, I really hate max. but it is quite easy to buildin GTKradiant and
convert to max.
As for shooting their foot, what did you expect them to do, build their own editor?
As for decompliling, you can view the levels in haloPC with sparkedit (just google it). But there is no way to cleanly decompile them.
Here is a link to the HEK(halo editing kit) tutorial.
it gives a good overview of what is needed to make a map.
Not sure where your getting that. where are the wide open areas?
My 9800 runs Halo just fine. I keep all the settings maxed, and most of time run 1024*768 but it occasional dips so I take it down to 800*600 from time to time.
Here is some usefull info on Halo's preformance.Gearbox did the best they could but microsquish had alterior motives for Halo and pretty much screwed GB.
So, yeah, of course HL2 runs better.
As Zell said, Halo was made for the xbox, as for it looking better on there, I can't comment because I've never had oportunity to play it on a TV big enough to see anything.
What sharp edges are you takling about?