I'm not really good at shooters, but that game didn't really was that frustrating for me. Maybe you are missing something that makes it more doable? I don't recall the section you are describing, it's to long since I played it. No help there, sorry.

Did you try to change the difficulty?

Do game on however, the ending(s) are very rewarding, imo. Great game design on the last few levels!

And yes, ever since the first elite, escort missions have and will all always suck.

Hey, make sure to at least try it on the hardest difficulty. n00b! Save the damn bullets, and use stealth when possible. Do not shoot things unless you really need to. I did it on the hardest difficulty, it is very possible. When you get to the toxic bubbles, note their spawn locations, these can be destroyed with a few bullets.

Also, time your movement. Your ally's movement will spawn one round of bubbles, and your movement will spawn another. Make sure to give him some room for him to go ahead first, that way it will be a lot easier to deal with one round of bubbles, instead of two.

Also x2, when you get to the metal room near the end of this section, just run and shoot the crap out of those bubbles following you, because once you're past the metal door, they won't spawn anymore from their spawn locations, and only you will have to deal with those already spawned.
That one is near the end, when you get inside the nuclear facility. Just before you use the crane to kill the 'boss', if that creature can be called that way.

I suck at stealth. I hate stealth. I hate it with passion. Any game that has stealth which I can't get past by shooting is unplayable for me. I even got trough stealth sections in Red Faction where you get a pistol with 18 bullets. Yes, I shot my way trough them, even tho it was nearly impossible. Now, to actually GET enough bullets I would need to revert by 3 hours. Funny part is, if the game allowed bloody saves, or at least put the autosaves into separate slots, I would only need to go back an hour. That is just sloppy, sloppy design - and Metro seems to have a lot of it. It seems that the creators basically thought "hey, all this stuff worked in STALKER, let's do it in a linear shooter!" But guess what, STALKER has avoided dead ends by - dingdingding - BEING OPEN.

I hear you. I have had games ruined by really annoying sections that just aren't worth it. A lot of times it happens toward the end of a game, which drives me even nuttier.

I enjoyed the game, been quite awhile since I played it, I do remember a "stealth" armour set though that allowed you to move silently, iirc you buy it from a trader at a station.

I dont remember it being difficult, I do remember a big WTF moment at the end that annoyed me, but later someone explained it in dumbese for me, so I had an idea what was going on, I'm looking forward to the sequel.

I get you, but there's not much else you can do. When playing Metro, the greater the difficulty, the more stealth you would have to use, because bullets are so freaking rare.

I really wish developers would learn that escort missions are NEVER EVER EVER EVER fun.

Sorry, but qouted for the truth! I mean sure - one escort mission per RPG would be a bit gratting, or tiresome, but it would be a blessing if they would really lighten up on those escort missions (hell no matter the genre: Action, RPG, TPS, FPS, RTS, ect, ect.. You loathe it to no end).

Anywho! Metro has always been the what if to me that filled in the European, Russia stories to my Fallout series. I love Fallout, but I garuntee anyone who has played it can relate when I say we have always wanted to know what happened to the rest of the world. Thus far I'm certain Europe is doing better in Fallout then the Americas (they've certainly implied as such).

There's only one case of well-done escort mission that you can't fail I have ever seen: Sections with Alyx in half-life. She was:
a) nearly immortal
b) faster than you so she was never slowing you down
c) smart, she took cover, ran away, etc.
But yeah, any studio that doesn't have money for proper beta-testing should be banned from making escort missions. They should also be banned from disabling save / quicksave function, I mean at the very least they should have allowed saving in different slots in safe locations.

The single best example of an escort mission done right I know of is the cel-shaded Prince of Persia. The entire game is one gigantic escort mission, and it's never a problem because Elika can take care of herself so well you could even argue the player-controlled Prince is the one who's being escorted here.

So escort missions can be fun. It's just very, very rare.

They would be bearable if you could give the escortee orders, or at least tell them to FRIGGIN STOP. Instead, they usually do everything they can to get killed.

Btw, that reminds me of the most hellish escort mission in a game ever. In the demo of Gunship!, a helicopter game, you had to make sure a group of friendly vehicles reached the other side of the map. But you couldn't give them orders, they just rushed into the enemy. If you tried to catch up with them, you got shot (it was very easy to get shot down in that game). If you played it smart (flying close to the terrain, using trees as cover, etc) you couldn't keep up with them and they got killed. Long story short, it was impossible to complete that mission. But the best part: I asked some experts of the game on a semi official forum how to complete this mission. Their answer: load it up in the editor, and decrease enemy numbers. :D

Well, PoP 2008 was the first example that occured to me, but then I have realized Elika is more of a game mechanic herself than an actual companion.

True, but you could probably generalise that's why the whole escort thing works. It has to be fully developed (like in your HL2 example – I'd argue the Alyx & flashlight section in HL2E1 turns the cooperation into a game mechanic), not just something thrown in without much thought.

And in the beginning in Gothic, you were escorted by the npcs. Quite handy to do some XP farming early on.