it looks like you are hitting some of the performance indicators but others are looking a bit squishy.
check this in depth review here: http://www.bjorn3d.com/2012/04/2x-kingston-hyperx-240gb-3k-ssds-in-raid-0-configuration/#.T-mizXJqnZ8
Your 4K is better than average, your seq and 4K 64Thrd is low and access is right where you would expect it.
It could be that your MOBO controller is reaching its max... but not too sure. Also firmware should be checked if you have the latest version.
Larger SSD's tend to be a bit quicker, so I am not sure if this is the cause for your lower than expected seq and 4K-64 scores.