IXOXI: I am currently playing original Thief Gold under Linux and I am astonished how easy it was to run it including EAX (which is usually removed in remasters). Nostalgia made me play this game, but I was shocked how bad level design is there. If they do remaster, it would make sense change levels.
atarirob: Nightdive have overall been pretty faithful with their remakes - to my knowledge they've never gone out of their way to alter a game's level design arbitrarily.
As with most things Looking Glass made, they likely ran out of time and money by the end of the project and just had to go with what they had, and it definitely shows in some levels. That being said, 'Thieves' Guild' and 'Bonehoard' are some of my favourite missions in the series. If this is your first playthrough, I'd recommend going back and playing the game on lower difficulties. Expert can be gruelling at times.
Played demo when it was published in nineties and later tried to play it a few times, but always was disappointed after a few levels. I already finished third thief, but never first two. It seems to me, that game should be played on expert as it increase difficulty and make player more focused. Now I would like to finally finish first thief and later second. Wish me luck. ;)
From Nightdive was great release Chasm: The Rift, it was instabuy and up to today best quake like game in my opinion, I like it more than original. Other adjusted games are not so great, e.g. Blade Runner is disaster, but also other game was often defeatured, for example removed EAX support which add another level of experience. Graphics can be outdated, but great sound is timeless.