retake if you genuinely believe you can do better. i had 2350(CR760/M790/W800) in december. i'm retaking because i've had multiple 800s for CR in the blue book and 790 math was due to one simple misreading.
IMO 2350 is good enough. True, you think you can achieve a perfect score but what would colleges think? Anything above 750 in every subject is near perfection and colleges would rather see that you focus on EC's after you're done. And now some schools are forcing all scores, nullifying score choice.
My parents are definitely making me take it twice, unless I get a 2400 the first time (which is highly unlikely). As long as I get 2300+, I'm fine - I have a pretty packed summer schedule and I don't want to use any of that time prepping for SATs in Oct.