too early to move to $2/4

I've been playing Party .50/1 for about 3 months and took advantage of several bonuses, so my total bankroll is about $1500. I've been beating .50/1 for over 2 months now and was thinking of moving up, since my bankroll would definitely allow it. After browsing through some forums and also according to my PT database, it seems that 1/2 is actually a little tighter than 2/4...maybe because of all the bonus clearing going on at 1/2.
For 2/4, I have a about 400BB, which should be enough, it might just be my lack of long term experience that would not make this a smart move. Should I stay at my current limit, even though my bankroll is larger than that?