No, I'm asserting that each PC requires more experience points to level up in 1e than is required in 3e and that the experience awarded is significantly more in 3e.
Once again we are back in to comparing apples to oranges and coming to conclusions based on raw numbers taken out of context. Two hundred is more than fifty, so two hundred pennies is worth more than fifty dimes right?
Third edition was designed to allow you to level after roughly 13 encounters. So first of all, you are either doing your math wrong or you don't understand the system. I think you are basing XP off of CR rather than EL, except maybe you are confused about the CR of the foes you are selecting. I also think you are using static values for the XP, not normalizing for difficulty. If you killed 4 skeletons as a first level party, you'd each earn ~100 XP - not 300. If you killed 4 orcs, you'd earn about 150 XP. Yes, this is more than the about 20 XP you you'd earn for fighting an orc armed with javelins (missile attacks earn it an XP bonus, plus XP for the hit points) and scimitars, but also very very critically, in 3e you earn ZERO xp for the treasure you recover. Whereas, in 1e, every gold coin you haul out of the dungeon is worth XP and on average monsters in 1e AD&D - especially when encountered 'in their lair' - but even when encountered as wandering monsters carry treasure worth slightly more than their XP value. In short, even in the most stingy campaign based on strict adherence to the random tables in the back of the monster manual, you are going to earn about as much XP from treasure as you would from killing monsters. If you use the tables in the back of the 1e DMG, then you'll earn more XP from treasure than monsters. And if you play 1e modules, you'll earn more than twice the XP from treasures as from monsters. And at that point, the gap between the two is closed.
I linked you to a thread which proved the assertion that if you stuck to published modules 3e leveled up no faster than 1e.
I remember when 3rd edition came out reading about how leveling would be faster so that the players wouldn't have to spend so much time at each level.
I'd love to read that. As I said, this topic of which one plays faster is one that has been discussed at great length at EnWorld. The short answer is that it really depends on how you play each edition.
PCs of level 1 in an encounter with four orcs in 3e nets the PCs 300 xp each for defeating them. Then an encounter with four skeletons nets them another 300 xp. At that point, they are nearly two thirds of the way to level 2 and after only 2 encounters. Throw in one more encounter and they just about have it.
It's very well documented that by design it takes roughly 13 encounters to go from each level if you stick to the 3e rules. The only way to speed that up, assuming a balanced build, is to risk frequent character death. You certainly don't level up in 3e after three encounters with things like 4 1/3 CR monsters or 4 1st level warriors. I don't know where you get those ideas, but if you played 3e that way, yeah, it would go fast. However, I refer you back to the thread for the actual math.
I really don't see how you are reaching this conclusion. Skill checks have nothing to do with leveling.
You earlier in this thread asserted skill checks slowed play. The slower that you play, the fewer combats you can do in a session, and therefore the less XP you will earn per session.
And combat better run faster in 1e than it does in 3e because you would need MANY more creatures defeated to come close to the xp that gets awarded in 3e for defeating monsters.
Once again, this is simply not true and more patient people than myself have compiled the numbers to prove it in the case of modules. I can also show you numbers for average treasure per monster that demonstrates the gap is not as big as you make it as well. Now granted, if the DM is stingier with treasure than any of the 1e guidelines in the MM, DMG, or published adventures, then because treasure is such a big part of 1e experience levelling will be significantly slower. But then, you are no more playing a normal game of 1e than a guy who uses optional rules to reduce or increase XP awards in 3e is playing the normal game of 3e.
But each orc isn't going to be walking around with 290 gp worth of treasure to make up the difference in xp as awarded in 1e vs. 3e. He might have a handful of coins at best.
Once again, either read the thread I linked to, or I can get you the numbers for the average treasure per monster slain to show you that you are vastly exagerrating the difference between the two systems in normal play.
I understand what you are saying about the treasure ratios in modules. They are placing more treasure on average than an individual DM might give out in his own adventure creations.
On this I'm fully willing to agree.
However, many of the potential treasure rewards end up not discovered, at least in games I have played in or run. They are often hidden in such a way that the players need to be super explicit or they won't find them.
Now you are sounding like me in that other thread. Nevertheless, while I agree with myself, the point remains and is well established that if you are playing modules - and by your own admission you are - the leveling rates are comparable between the two editions. The modules don't work if a significant portion of the treasure is unfound because by design enough treasure is available to level the PC's up to be able to face the next encounter or next module in the series.
I am fully aware that an individual DM could make leveling in either 1e or 3e faster or slower based on a huge variety of factors but by the book, 3e seems to favor faster leveling.
This is a perception bias. Whether it is based on experience with particular DMs, or on misunderstanding the system, or on what, I don't know, but the facts don't support this conjecture. If you had presented yourself as the sort of DM that doesn't use published modules and which stuck to the MM tables and randomly placed treasures, then it would be easy for me to explain the origin of your perception bias. However, I just linked you to a thread that proves numerically that the 3e conversion of Temple of Elemental Evil and the 1e module level at almost exactly the same rate. I don't know what else to tell you.