Speed of leveling & it's effect on a game, has entirely to do with how the rest of the game is balanced.
Ex: Take Fallout 3. Lv20 cap, one perk per level, 10-20 skill points per level. X amount of XP needed to hit lv20
Now, multiply the cap by 5, for a lv100 cap.
And divide everything else by 5. So, one perk every 5 levels. 1-2 skill points per level (let's say 1, 1.5, or 2. With 1.5 giving you 2 points every other level)
And divide the amount of XP needed for each level by 5.
Tweak the monster spawning tables to fit the 100 cap. (monsters that would spawn at 10 in original system, spawn at 50 in new one, etc.)
You gain levels five times as fast! The cap is an amazing 100 levels! OMG, totally different!
...except not. Entire game is exactly the same, except you hear the "level up" noise 80 more times.
So yeah. Sure. They're saying it's "faster" level gain. And there's more levels. But that doesn't mean that you'll instantly shoot up to being Wasteland Godling in two hours of play. It's a different system, balanced for it's own game. Relax.
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Only one of those I had any issue with is Fallout 3. Not because the lv20 cap was too low, but because you got to it a bit too fast (my original char was lv20 from doing sidequests, before I ever got to GNR in the main quest). Now, my solution would have been to increase the XP curve from lv11-20, not add 10 more levels like Broken Steel did.
(It's also kind of funny that they say FO4 will level "faster than FO3, more like Skyrim", because I think FO3 levels faster than Skyrim, so.......
It may be a perspective thing, though - if they're talking about individual FO3 levels, then sure. They come a bit slower than Skyrim levels. But with the lower level cap, it's effectively more gain. So I hit the cap long before finishing the MQ in Fallout 3, but I was only level 50-55 when I "finished" my first Skyrim character. And her main skills weren't all 100's.... I could have leveled her further without using new playstyles.)