I'll voice dissent at the notion of the 1e model being a good one. It used to annoy the snot out of me that people would want to quit playing the characters just at the point that their abilities became interesting.
Also, I think that it's relatively trivial to regulate advancement rates with numbers. The number of XP to advance a level is 1000 x current level. So, if you want to advance after X hours of play, simply have your awards average level * 1000 / X. Yeah, you could just advance the characters every 20 hours of play instead of awarding them 50 * level XP every hour... but in doing so, you deny yourelves the psychological benefits of token economies. Given how trivial that math is, I rather think I reap great benefits in player enthusiasm (and overt GM manipulation

).