Well I'm patched to 1.06, which is I think the latest, but now that I think of it, I may have applied the fullscreen tweak when I was on 1.05. Come to think of it though, I did reinstall the game when 1.06 came out, and I'm pretty sure I had to apply the tweak again because it said BorderlessWindowed, not Fullscreen. Are you sure you applied the tweak to the right .json file? And are you sure you applied no other tweak prior that may have applied such a thing?
What difficulty were you on when you just ran through the conveyer belt segment? I tried that and had no luck at it on Hard.
Yeah the battle with Gonarch is epic, pretty much every stage of it has you on your toes and a bit scared like you said. There was only a quirk or two in that segment for me, where for some odd reason the gas jets near the web gates would not light with flares no matter how I tossed them or even walked to them with one in hand, but a pistol shot, or even a crowbar whack would do the trick. LOL
I don't really recall how the original compares in gameplay, as it was so long ago that I played it, and I really don[t know where gameplay content was added. That's why like I said earlier I was scouring YouTube to see if there was by chance a video showing all the added content, but struck out. If you manage to find such a thing, please post it.
Yeah this play through Xen seemed to go much quicker, but that was due to having refreshed my memory on the prior play through regarding where to go in places I was stumped, where to expect tough battles, and how to deal with them. It's a great game, and I agree, so well honored by Crowbar Collective's Awesome work.
I'm having a lot of fun with HL2 as well, and I can't wait to get to the Striders and Gunships. The Antlions are pretty awesome too. Honestly, my only annoyance with HL2, is the friendly AI don't follow your commands as well as in HL1. They will for a few seconds, then come back and get in your way instead of staying put when you issue a no follow command. This becomes a real nuisance in narrow hallways and stairways, especially when you're retreating to them to use as a choke point for Manhacks. To add to it, they always get all apologetic when they bump into you and say "Sorry I'll get out of your way", to which I always say, "Just STAY out of my way!"