AbdulAlhazred
Legend
[MENTION=996]Tony Vargas[/MENTION] has spoken in favour of "filler fights" in 4e. I'll approach the issue from the opposite direction: Night's Dark Terror doesn't have any filler fights. It's a tight module. I think 4e suits it better than its original system did!
I can also report that its maps were fine. Yes, the goblin warrens involved some fights in labyrinthine conditions - but isn't that what goblins are all about?
The other classic module I have converted to 4e is G2. In this case, again, there was the need to assign frost giant stats to the many, many giants in this adventure. I departed more from the original in this conversion (eg turning visiting giants and ogres(?) into visiting eladrin of the Winter Court, as fitted with my campaign backstory). But the maps were fine - some huge distances, which 4e tends to love - and it was a lot of fun.
I have to agree with you, I don't find filler fights to be terribly useful in 4e. Not that you NEVER have them, but I don't tend to treat "there's a couple orcs guarding the door" as a fight. I just let the PCs expend some resources to make sure said orcs are insta-ganked (or not and they can deal with the general alarm). Its possible you might have an RP encounter at other times, the bad guy just surrenders, plays dead, whatever.
Its possible a goblin warren full of labyrinthine passages might work, if you handle it correctly. I did any number of very limited dungeon crawl type scenarios that worked fine, you just had to limit it to say 5 encounters or so, or invoke an SC, etc.
G2 is a bit weird, there's a bunch of it that is outdoors, and even the main giant lair parts do have a lot of space. G1 and G3 are both a lot more constricted, the areas are reasonably large in them, but the giants are HUGE, so it still tends to turn into a crowd of monsters standing around swinging. I've always kinda wanted to try running Chris' G-series conversions and see how it worked out. I'd note that he definitely reworked a lot of the maps and encounters. It looks more like a 'based on the 1e module' kind of thing rather than a straight up conversion.
I'm sure you could run the whole GDQ series pretty much as-is in 5e.