Damn, I was just working on the same map today! I didn't get as far in recording as you, but it still managed to be faster due to me using pretty much the straight max route with a few changes such as running past the 4 chaingunners in the beginning like you did.
An attempt at Alien Vendetta, MAP28 with -fast monsters. Demo length: 20:44. Monsters: 232 killed, 72 left. Recorded with PrBoom+ 220.127.116.11 with -complevel 2, so should playback with vanilla.
The demo itself is very slow and rather uninteresting, maybe for Revved... This is what I think in general:
Every single area is very beatable, the problem is not to die in one continuous run. First cyber: run past it, when you return have much health (200/100 is preferable), so you may survive getting hit by a rocket when you teleport back. Second cyber: not much of a problem. Third cyber: this is the hardest one, I think, thanks to that bloody chaingunners which miss their shots, hit the cyber and awaken him (this is where I died). Fourth cyber: should be easier on UV-Fast than in UV-Max. I think I'll make it sooner or later, but I wouldn't mind anyone else trying it :) Also, maybe some ideas for the third cyber to kill him in a consistent, safe way?
For this, I combat with a failed attempt at Alien Vendetta Map 26
with -fast monsters. Demo length: 20:46 (the irony) Monsters: 770 killed, 194 left. As you can see, it is very much beatable, as such with the ending. I just mucked up one part with the arch-viles and ended up getting killed as well as not taking safe caution with the revenant hordes.
This has been downloaded 152 time(s).