Kernel Preempt?

["Brian C. Huffman" <huffman graze net>]

I see that preemption is disabled in the Fedora Core kernels.  What's
the reason for this?  I've searched the lists and haven't seen any
definitive responses although the possibilities range from problems w/
SMP to difficult to reproduce issues.  

I'm running a Toshiba Laptop and I'm currently in the process of
tweaking everything I can from a performance point of view (since
laptops are inherently less responsive than desktops) and I'd like to
know if 1) enabling this is dangerous and 2) will I see a perceptible
latency reduction thus an increase in user experience?

Thanks in advance,
Brian