Dante I dont play 2/4 but I lose more at NL than I do at 3/6 and 5/10. I don't have the game to know the proper betting strategies and extract enough value when I have the best hand and protect my big pairs from being cracked. I also still find the my KK, QQ, AA, JJ being cracked even when I'm all in preflop against hands like KQs, AKs, and weaker pockets like JJ, TT, 99 etc.
With that said, I do believe that a player could make SUBSTANTIALLY more on $25 NL at Party if he was a good NL player. Frankly, I don't think I'm that player and I refuse to think that it is just my "luck." When I do play NL I consider it a lesson and when I win great and when I lose it is just the price of learning how to play the game.