Party 2/4 verus 3/6 question

Ive mainly been playing a lot of 2/4 limit at party and found that the games seem to be the softest 2/4 games that Ive found.

Im wondering, let's assume that I had the bankroll to play either (maybe over 2000), and I had the long term results to prove that Im successful at 2/4, is there any reason to play the 3/6?

What are other peoples experiences that have played both of these.

Also I mainly only play full tables and not short handed games.