It seems that most role playing games have a sweet spot - that magical range of levels (or points in point buy games) where the game plays best. In D&D, I always considered the sweet spot to be around levels 4-9. Before this range, characters can be cut down by goblins, and every little thing is simply a struggle. Past this range, players just seem to get more powerful rather than more cool. As a GM, it's tough as hell to run a challenging, interesting, and fair game for characters that can cast wish, teleport anywhere, and shoot instant death rays from their pinky fingers.
But somewhere in this range, something wonderful seems to happen. The power levels of the magic users and fighters seem to cross. Everybody gets equal screen time. Characters get a variety of new abilities that are simply cool - I was playing Osric today, an old school D&D clone, and I noted that my druid character would get shapeshift 3/day at level 7. Imagine a party in need of recon. The druid turns into a small bird and flies. Wow, look at all that shiny stuff down below the trees! Wait, what's that coming through the clouds. Wyverns. Crap. A chase ensues, straight back through the trees and to the party. Magically powered chaos. Now, that's cool.
So, let's say that you buy my argument that games do have sweet spots. Once we've identified the sweet spot, what are we to do about it?
Should we work our way up to it, bit by bit, so we get that (ahem, plodding) thrill of character advancement through blood, sweat, and tears? Should the GM just fudge XP so that characters get to that sweet spot faster?
Neither, I say. The reality is that most of us don't play in a single campaign for longer than 10 sessions, and that's really pushing it. My buddies and I just counted how many different games we've played over the last 3 years, and the answer was somewhere around 12. A 4-5 session arc is the norm (at least, for us), and then we're off to a new game. I know most gamers out there don't have solid enough of a group to even play this much.
So, I say start the game in the sweet spot. Play the game where it's at its coolest.
(For what it's worth, these thoughts are in response to some of the games - both very high powered and low powered - that I've been playing lately. And the grief that Pat's been giving me about always wanting my characters to succeed. It's not that I always want them to succeed - I just want them to have the opportunity to do something cool. Playing in a game that's set at the sweet spot seems to be a key to this).