I chose STEADY. Here's how I justify it:
As from my martial arts days, it was observed that Americans like recognition and signs of progress. Hence, they added lots of stripes and colored belts. Versus really old-school martial arts hands you a white belt, and you become a black belt by virtue of it's age and dirtyness (rubbing it in dirt is cheating, the implication is the grime build up from training is what causes it to shift from white, to brown to black).
So, from this, we take that our players mostly like seeing their PC advance. Getting XP and gaining levels is the RPG dashboard for progress.
I also accept as true, that the longer the time gap between sessions, the faster progression you should use. Conversly, if you play every day, you should slow things down. This is because for the former, if you only play once a month, players will be less likely to feel like they are getting anywhere. If you play every day, it becomes silly for them to reach level 20 in a month's time.
i also simplified/misinterpreted the 3e XP for encounter math to hand out 300 XP times CR divided by number of PCs in the encounter.
As such, the whole thing can be systemetized.
Since we know the expectation is 75 XP per CR per encounter for a PC (which is a new level for 13.3333 encounters) we have our basic pace established. Level 1 PCs are expected to face CR1 monsters, level 2 PCs are expected to face CR2 monsters, and so on. The result is that we're really working on a scale of 1000 XP per level when PCs are fighting level appropriate encounters. Because the XP chart is really level times 1000, it provides buffer if the PCs go slumming against weaker monsters, so they don't get as much actual XP.
Back to that scaled 1000 XP per level. As some other folks say, they advance the party as desired/needed. You can do this formulaicly, so the players are still using XP, but in reality, they advance at a controlled pace. Or you can use this metric to test/moderate the XP amounts you hand out in other methods.
First, figure out how much real time you want to require to advance from level 1 to Level 20. Let's say 1 year.
Next, determine the number of game sessions you'll be having in that time frame. Let's say we'll meet twice a month. So that's 24 sessions.
(1000/24) * 20 = 833 * Current Party Level
This gives us how much XP to hand out per PC at that session, as appropriate for their level.
Note that I asked how fast you want the PC to reach level 20. Rather than asking how many sessions to reach the next level. While I could provide that math (it ain't hard), doing so frames the problem wrong.
Saying "I want 3 sessions per level" doesn't acknowledge that the group plays daily, or plays once every 6 months.
In actuallity, old WotC surveys indicated that few campaigns last longer than a year. If you only play once every 6 months, and don't level up after a year of play, you may lose interest, further ensuring that the campaign doesn't last. So, the stereotypical gaming group needs to be a bit more generous with the XP if they play rarely.
So, instead, I frame the problem by looking at the player's end goal, reaching level 20 (that's not their only goal, but it's their default PC advancement goal). By determing how long to reach that sounds fair to your taste (I don't assume 1 year = level 20 = acceptable), you can then evaluate your group's frequency of play to support that pace.
Once you've got this basic pacing metric (say 833XP per level), you could divide that by 13.333 to get a per CR amount of XP to hand out. Remember, the 3e math assumed 4 PCs, so it should factor that back in.
(833/13.333) * 4 = 249 XP per CR for encounter as Party XP
An obersavation, having just done the math here. My brisk assumption to have my players reach level 20 in one year gives less XP than the standard 300XP/CR expectation of 3e. This confirms that D&D 3.x did have a faster than many GMs may have preferred. I can't say what the average GM prefers, but I think many would say that level 20 in one year is faster than their default assumption or preference.