Welcome back Giest!
I played through the beta version and I must say these levels were quite fun to play, and looked nice as well. They get progressively better looking, too. I never really had any problems with ammo, but I did play conservatively, so the ammo balance might be just right (I played on HMP - I assume there's more monsters on UV). I liked how there was a boss at the end of each level. A Duke-monster or two caught me off-guard on a couple of occasions (you know those brown bastards that run around fast). I died once to the boss of the 3rd level, but I figured out his attacks well enough to beat him on the second attempt. My favourite boss fight was actually the first one, with the shadow thing in the dark room, making the fight a bit more tricky and nerve-wrecking. The bosses in general are sort of kill and varied enough, and the level 3 boss is awesomely huge with a lot of appropriate attacks, and requiring you to "figure them out" I felt I got a bit stuck in the walls from time to time in that level 3 boss room, though. There seemed to be an overabundance of Medikits in some areas, particularly in the second level - there seemed to be quite a few Medikits in the nukage there. The Duke 3D monsters felt somewhat out of place.
The cutscenes I found terribly silly, and while they were somewhat funny, I felt it sort of took away from the atmosphere. I think it would also be great to have them completely skippable. One method that could be used is perhaps to use delays for the conversation rather than having them switch on hitting the USE key. And then instead hitting the USE key sets everything in place and skips the cutscene altogether. I haven't really played the original wow.wad, but I'm assuming the cutscenes are silly due to that. Personally I think the WAD as a whole would rise if you reinvented the cutscenes to something more serious.
I remember playing through some of your really early work a long way back while I was working on Titan and releasing the beginning levels individually for feedback, and sort of thought of us as "n00b mapping buddies" back then. You've sure improved on your mapping skills since (but you're not the only one!

).
Since there were only 3 levels, I decided to play them all through in one go while recording a demo, and hoping they were short enough for me to finish before I needed a break. I managed to complete it, although I guess the demo stops when I get killed by the last boss - far as I know it doesn't continue recording after you load a saved game? Though if it does, you get to see the boss kill as well.
Here's the demo, recorded on GZDoom 1.1.4:
http://rapidshare.com/files/141265352/ixepic01.zip.html
EDIT: When I played through the demo it seemed to desync at the beginning of map 2.