It's so rare for us old timers to hear of an "Aliens" newbie and personally, your thoughts would be fascinating to me.
I'll try.

Watching both movies was equally fascinating to me, in terms of seeing the inspiration for so much sci-fi since - from
Starcraft's shuttle operator saying "we're in for some chop" to
Avatar's cryo to shades of
Trek's Borg infestation.
For instance - how does the actual LOOK of the film hold up for you, since it is now 26 years old? Does it still look good? If it does, do you feel this may be due in part to no CGI?
1. I was surprised to find that after the 2.35:1
Alien,
Aliens was 16:9. I was initially disappointed, but while it looks less epic, 16:9 does give a more "you are there" feeling, which works great.
2. While I was a bit disappointed to see people walking around the planet without bio-suits in
Aliens (I know, terraforming and all, and I got used to it, but still), I thought both movies looked fantastic - especially the exo-suits, which I couldn't fathom until listening to the commentary!
I very rarely have complaints with modern big-budget CG.
The Last Starfighter's ships looked fake, the Scorpion King from
Mummy Returns could have been better and the Arnold T4 "cameo" was impressive but not photorealistic, but that's about it. I'm pretty forgiving about that sort of stuff, particularly given the expanded scope it's given movies overall.
Also, lots of people say CG is distractingly fake, but I often think the same of models. When I see
Aliens' exosuit, for instance, I say, wow, that's totally believable. How did they do it? So, I'm taken out of the story either way. The art of the script and acting is the important thing.
That said, I hardly think that the film could be at all improved, image-wise. Though I love modern digital color grading, it was awesome to revisit the era before lighting and hues became so wonderfully precise, and the relative lack of contrast may even make the movie more unsettling now than when it was made.
The key feature of CG, imo, is that it allows the impossible to be done so convincingly. The benefits are obvious - Gollum, Iron Man, Davy Jones, etc. The downside is that it's elbowed out nearly everything else. Unlike
Lord of the Rings,
Aliens doesn't need CG because its humans are just plain humans. So CG isn't the problem, the problem is that not enough big-budget, A-list action movies about regular humans are being made. Case in point: Indy, so human in
Raiders, takes a dozen or so ferocious hits to the face in
Skull, and doesn't look any worse for it - L&S forgot that Indy isn't Kryptonian. (Which gives me a great opportunity to give my beloved
The Mummy a shout-out - it's thrilling because the humans are human, and don't do any egregiously unbelievable stunts!)
I am, after all, one who not only believes that the
SW PT should have been made at the technical level of the OT, but in
black and white, too. But, I wouldn't change the CG prominence of
Trek XI. (The tone being a somewhat different matter.) Because the PT was meant to precede the OT, whereas Trek is expected to evolve with the times, somewhat regardless of when the stories are actually set.
Bottom line: lots of the technical aspects of
Aliens looked fake, especially the obviously plaster alien infestation stuff. But I loved it anyways for its artistic quality, just as I loved
Iron Man 2 for its artistic quality amidst obviously CG effects.
AND: Would I like to see Cameron refurbish the movie's effects with new CG? Hell, no! Would I like to see a masterful theatrical 3D conversion? Hell, yes!
3. I really hope Scott doesn't explain the alien ship or the Space Jockey. I'm all for expanding universes, but some things - such as Yoda's origins or how Superman shaves - are best left to the imagination. Also, I agree with Weaver's recent comments that trying to make a "new Ripley" is kind of lame - I love the Ripley character, of course, but why not have a different, even male protagonist, next time?
I'd most like to see a post-
Aliens movie that ignores all but the first two movies and shows us a totally different aspect of the universe, with a similar look and feel, but a different kind of story, maybe well without the Aliens at all. Of course, that does pretty well describe
Avatar.