Am I the only one who doesn't want a 'feeling of advancement' as a goal?
For me, I want to enjoy the level I'm at, to roleplay there without concern for the next level up, without expectations or hopes for the next level up.
I yam what I yam and that's all that I yam... Until I break through to the next level and evolve into something greater.
That's what I want, screw the fiddly advancements and feeling of progression, make every level a life changing event for the character.
In 3rd edition, a character's overall power is said to double every other level. That's decent, but doubling every level is even better (if that translates to half the total levels that's fine.)
Do not build classes where someone is stuck waiting for the next level, make them amazing classes where any level could be a satisfying place to spend an entire campaign if a GM decides they only want to run within one level.