K, currently playing a rogue...and i'm about 2-3 levels below the quest chain currently.

Now, does that one small level make a huge difference?

I was... (Defiant) doing the undead quest where i have to kill a random boss skeleton to get a key... and he was 23, i was 20...so i tried, he kicked my ass...i was above 2k EXP from leveling, so i turned in 2 quests, leveld, went back and utterly destroyed him..no new gear, he was full hp...nothing was changed.

Does 1 level really make that much of a difference? Like, i barely hurt him at 20, and he didn't touch me when i got 21.

Yea, just like you said. You should also start missing like crazy when attempting few levels higher mobs.

yes, but not as much as other games....

pvp-wise the lvl difference matters much less than in other games, but in pve levels do seem to have a steeper scale.

+1 and +2 there's no real noticeable difference from even con, +3 and you'll have a 30-50% miss/resist rate, they'll crit you a lot more often, and in general there's simply no reason to quest beyond +2s. Only exception is if you're a healer and questing with someone a lil higher lvl than you, or instancing as heals.

This