Yeah. I haven't seen a level 50 yet, because after TVHM I started a new character instead of playing through the DLC again. I would be curious to know if there were any difference, because the buffs at level 30 are not inconsiderable.
Edit: OK. It looks like there probably are differences. Six skills can be buffed from +2 to +5. The level 30 I saw buffed them to +3, so there's room for improvement.