The XP per Opponent ratio seems notably lower.Yeah the main reason I'm asking is our "X" in that X sessions we level is based on how we leveled in 3e.
If 4e assumes a group levels a bit quicker, we might take that into account in our group.
Don't know how its supposed to go, but we've found that its roughly every 6-9 encounters for us, depending on how hard the encounters are. Our group plays about 4 hours a week, every week since 4th edition came out in June and we just hit 6th level. It seems faster, but we like it that way. We also keep track of XP as a group score - we all level at the same time.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.