I'd do it even if the xp penalty stacked - I still have no problem reaching level 50 in all my characters with the Lesson Learned perk. In New Vegas there are tons of quests, and many enemies give 50 XP, which was reasonably rare in Fallout 3.
Most criticals come from sneak attacks, anyway. Focus on melee weapons that have a bonus to crit chance and/or damage - the Broad Machete you get from the starting equipment DLCs will do you for a while, or the Machete you can find in the abandoned shack just north of the Yangtze Memorial. Unarmed/Throwing Weapons Build: FrizzleFry: 2: 8/5 1:43AM: Thank you interplay. The casinos don't use real shoes, they just randomize what card comes out next based (I guess) on your luck skill alone.