Oh I have no doubt, but it'd be a huge time-sink to fully experience its worth (I imagine, having never played it!). I'm just not the kind of gamer to visit oldies if I missed them in the past - no matter how good they might be. I seldom find the time to sit down for more than an hour or two per night as it is to play newer releases!
The original is a massive time sink - back when they made games that you could easily sit through for the best part of a week rather than complete in an afternoon :S and if it half way interests you there are tons of sub/alternative plot lines and story threads that serve for atleast another play through after the first.
The one aspect where it doesn't really stand up well IMO is that a lot of the levels are like running around in a concrete dungeon :S the storyline and overall atmosphere masks it a good bit but it gets a bit much now coming from games with more varied and visually detailed environments.
While graphic mods go so far in some ways they only serve to emphasise how blocky the geometry is - a super high res texture coming to an abrupt badly aligned edge doesn't really look that great :S
I'd love a direct HD remake with a few tweaks to the environment and modernisation of 1-2 mechanics but largely level unchanged - the revision mod does a really nice job of staying true to the original while adding gameplay depth/fleshing out blander areas of the original game but still looks dated visually.
https://www.youtube.com/watch?v=TjGcXPu7RVc
(I'm quite impressed with some of the additions they did to the demo levels).