I've been enjoying NV quite a lot and I'm not 24th level. I'm noticing that some spawned encounters are gaining more opponents or better opponents. I never was able to finish Oblivion because I didn't care for the scaling that went on in that game. I'm just wondering how much actually happens in NV? If it's minor then that's fine, I just don't want it to be completely linear in terms of your power.

It does not scale as much as the big O... at least it did not ( this latest patch tweaked some new content so I'm not sure about now. )

Basically certain encounters will get switched out with different versions at higher levels..
such as feral ghouls may later on switch to feral ghoul roamers, or Nightkin switching to nightkin masters at repconn.

Weapons on npc's before the patch did not level ( this led to gangers like vypers not spawning with their full equipment lists ) as they have a static level set in the GECK.
After this last patch they now should do, so there may be more leveling seen in game now.

The only ones that should level fully are mission specific encounters.. Ceasars legion centurians and NCR trooper / rangers close to end game.

Edit: my freaking Avatar switched back to Elmo on its own wtf???

DLCs are more or less scaled.

That's strange, I had not noticed that the game scaled the encounters depending on character level.

In my mind Vault 34, the Brotherhood of Steel, and robots in general seem very highly tuned. To me they are the 'hard hitters' but I'm also now a hard hitter, so perhaps they aren't the same creatures had I found these places earlier. I wonder what it's like to climb Black Mountain at level 6 lol...probably the same experience as I had at 30 if I had the guts to find out where that radio signal was coming from before it kept going out and didn't want to check out another area.

The only other rpg game I played where enemies and friendlies scaled towards level was Final Fantasy 8 on playstation. F:NV does it much better with subtle differences that you can act and react towards, and the difficulty slider reigns supreme to adjust much more than perks and SPECIAL.

Haven't tried the DLC yet, but in my opinion the options are there you just gotta click 'em to suit your style at the time. Some days I'm so slow that my crosshairs* can follow a mob but score no hits, the exact same way a character feels when he steps out of Doc Mitchell's house. It feels the same to me when I log in now, as what it did when I logged in months ago (except I have more irl knowledge of the terrain and higher rpg skill levels). Other days a hacking attempt will take me forever to find the right code. I will probably stay level 30 for DLC since I'm satisfied with my guy.

*usually faster at recognizing , anolyzing , and removing a threat better than skillchecks and V.A.T.S. on easy mode, but It would be a whole different story if I were off my game and not playing to my character's strengths.

One instance that I recall was Caesar's Guards not having the same uber-fist weapons if you rushed to the end game at a very very low level. But I don't know if that changed with a patch at some point. I haven't tried to do the Fort at lvl 4-5 anytime recently.
But I think how it worked was stuff like the stronger NCR troopers used to not spawn until you reached a certain point in game...which by then, most people would be higher level.

In terms of general human enemies gear scaling up - like the bandits - they tend to do so the first time around clvl 8 or 9 I think, but not sure if/when they do again. I've never tried to find out for sure. Should be noted their hitpoints etc. don't increase (last I knew), and I've never seen them wear higher level armors, either...only their available weapons change.

Only very few NPC's actually scale with you. And the DLC of course.

The most distinct scaling I noticed was where Moe spawns. There was a LOT of centaurs and evolved centaurs when I went there at high level. A whole lot of them. Made me wish I was an Explosives character.

Equipment lists have their own scaling as well.
Generally the way the game handles leveling is in three tiers.

Type / degree of challenge of creature.
Ghouls have 4 types.. Feral, Roamer, Glowing one, Reaver.. placement in game allows you switch out these types based on player level and how common you wish the harder creatures to appear.
So at rep conn, early - mid level it should look mostly the same, higher up you'll see lots more roamers, plus most nightkin are nightkin masters in the facility.
Or on Blackmountain, the centaurs then switch to evolved, the SM's may switch from super mutants to brutes, to masters... ( but likely start at brute level as it's a higher level area. )

Level.
Most creatures NPC's had a static fixed level in NV, this means no matter your level the npc's are the same level as they started with.
Which means no boosts to stats, health, skills.. etc.
However some do level at different rates, in my game I set most to level at between 50% to 66% to player level.
So some foes you face.. in particular NCR or CL ones end game will level on a one to one scale and have increased stats, skills, health.

Equipment.
Equipment is in its own leveled lists, if both a player and NPC are of high enough level.
And that NPC has a weapon in its list ranked at that level or under, there is a chance for said weapon to appear.
In Vanilla NV for ages certain gangers just north of Nipton should have had various weapons, but did not rather they were all armed the same.
This was due to being a static level 7, where there extra equipment was fixed at level 8.. so they never spawned with it even if te player was level 30.

Minimal and it's a huge problem because you'll be a god at high levels.