Take into consideration that the manufacturer's recommendations usually tend to have the car understeer so that regualr drivers don't get into trouble.

A couple hints to help you set up your tire pressure.

Higher all around= better overall gasmileage ( good for roadtrips like Expo), harsher ride, longer warmup period and possible premature wear in the center.

Lower all around= more drag, better launch grip, smoother ride, worse gas mileage, unstable car at excessive speeds and uneven tire wear.

Higher Front/Lower rear= general understeer
Lower front/ higher rear= general oversteer ( car gets loose)

Keep in mind these settings with all things equal.

In my case, I use 30 all around on RA-1's and I put 35 in when I do a road trip.
For autocross, I generally run the rears quite a bit lower to increase grip as I like to use off throttle oversteer techniques.

In reality, there are no right or wrongs, just guidelines to help you choose a setup that fits your style.

BBQman