I think it would be an interesting experience but probably not a satisfying one. As I see it, to be as strong (in character skill) at the end as you were at the beginning, one of two things have to happen:
1. You start weak and finish weak. This gives you games like "I wanna be the guy", which build player skill, but I haven't seen this in RPGs. If the player gets noticeably stronger and then weaker along the way, the part where the character's powers are taken away can make the player feel cheated. (Not always: see e.g., the last fight in Ocarina of Time.)
2. You start strong and finish strong. Everything is easy and boring, unless you are depowered along the way and have to claw your way back up. See Metroid Prime (1 or 2) on the GameCube, or Wonder Boy III: Dragon's Trap on the Master System (or Dragon's Curse on TG-16). Usually the strong start is used to ease the player into the game, so that it's harder to fail while learning the controls and patterns of the game. Regardless, you still have a definite progression: either of tools, stats or something else that means you can go to places you couldn't before.
Wonder Boy III is an interesting example, because although you start with the best armour and weapon at the start of the game (which you then lose), the various forms that the player takes (mouse-man, hawk-man, &c.) give the player a different kind of power than the one that was removed: flexibility of movement as opposed to better offensive/defensive stats.
Basically, characters do not level up beyond level six, but gain additional feats every 5000XP which provide various small bonuses. This means that the players still get more powerful, but they don't scale up into the world-destroying powerhouses that you get at high levels.</aside>
I don't think that getting rid of XP means that you should throw out the whole concept of power progression in an rpg-like game. You may as well tie power progression to items or other things that will happen along the way. If you have an XP system (with power progression tied mainly to XP), then you as a designer need to match XP progression to story progression. If you don't, players either need to grind (yuk) or everything's too easy because you're levelling too fast (snore). Why not throw that out and go with the metroidvania-style of getting more tools to solve your problems? Metroid did this especially well because if the current fight was too hard, you could backtrack and explore for more energy tanks, missiles and so on so you have more resources at your disposal.
1. You start weak and finish weak. This gives you games like "I wanna be the guy", which build player skill, but I haven't seen this in RPGs. If the player gets noticeably stronger and then weaker along the way, the part where the character's powers are taken away can make the player feel cheated. (Not always: see e.g., the last fight in Ocarina of Time.)
2. You start strong and finish strong. Everything is easy and boring, unless you are depowered along the way and have to claw your way back up. See Metroid Prime (1 or 2) on the GameCube, or Wonder Boy III: Dragon's Trap on the Master System (or Dragon's Curse on TG-16). Usually the strong start is used to ease the player into the game, so that it's harder to fail while learning the controls and patterns of the game. Regardless, you still have a definite progression: either of tools, stats or something else that means you can go to places you couldn't before.
Wonder Boy III is an interesting example, because although you start with the best armour and weapon at the start of the game (which you then lose), the various forms that the player takes (mouse-man, hawk-man, &c.) give the player a different kind of power than the one that was removed: flexibility of movement as opposed to better offensive/defensive stats.
<aside>I have read about an interesting house-rule for D&D 3.5 called "Epic Six", which gives a similar result but not using the mechanic you suggested: http://www.enworld.org/forum/general-rpg-discussion/206323-e...
Basically, characters do not level up beyond level six, but gain additional feats every 5000XP which provide various small bonuses. This means that the players still get more powerful, but they don't scale up into the world-destroying powerhouses that you get at high levels.</aside>
I don't think that getting rid of XP means that you should throw out the whole concept of power progression in an rpg-like game. You may as well tie power progression to items or other things that will happen along the way. If you have an XP system (with power progression tied mainly to XP), then you as a designer need to match XP progression to story progression. If you don't, players either need to grind (yuk) or everything's too easy because you're levelling too fast (snore). Why not throw that out and go with the metroidvania-style of getting more tools to solve your problems? Metroid did this especially well because if the current fight was too hard, you could backtrack and explore for more energy tanks, missiles and so on so you have more resources at your disposal.