Can you explain the difference? Do you mean awarding XP at certain times vs. as you go along? If so, that is how I do it as well. I only award XP at the end of an "adventure" (or during a milestone completion in the middle of a longer adventure - so for example when my group did Against the Cult of the Reptile God, they got XP when they dealt with the town threat allowing them to level up and then undertake the more harrowing swamp lair threat, after which they got more XP and leveled up again!).