The palm, which is probably the most critical area for protection, is completely covered with leather.  Fieldsheer calls it "aniline cowhide".  There are double layers of the stuff sewn over the palm, between the thumb and forefinger and a small patch over the heel of the hand.  I do feel a bit more confident about the protection offered here than the mostly mesh top side.

Fieldsheer also says that the palms have gel padding, but if this is true, it's the thinnest gel I've ever seen, because I feel absolutely no padding whatsoever in the palms of the gloves shown here.

The Fieldsheer Sonic gloves have a decent sized gauntlet for a summer mesh glove.  It secures with a smallish piece of Velcro over the wrist, which seems to be typical for this type of glove.  A section of elastic is sewn in to the top of the gauntlet at the wrist, but I don't think this will do much to keep the glove on the rider's hand in a crash.  Even with the gauntlet tightened up as close as possible, it's very easy to pull the glove right off my hand.

There are many tradeoffs when choosing summer gloves; maybe too many tradeoffs for a serious rider.  For those truly concerned about wearing the safest gear possible at all times, it may be better to sweat it out in a pair of heftier leather race gloves than to take the chance with a too-thin mesh that might come flying off at the first sign of trouble.

On the other hand, there are motorcyclists who subscribe to the theory that "anything is 100% better than nothing" (what I tell myself when I can only get out for a jog about once a week).  They may find that the Fieldsheer Sonic glove offers a reasonable compromise between safety and cooling.

I will say this -- the Sonic gloves are comfortable and they flow lots of air, and in ultra-hot weather, that may be all that matters if it's a choice of riding or not.

The Sonic gloves in size large are just about a perfect fit on my hands.  They have a slightly long thumb at rest that gives me enough stretch room when my hand is curled around the grip.  The fingers are slightly too short and the mesh fabric does not seem to be stretching enough over time for a nice broken-in feel, so I find that I do have to pull the gloves at my fingertips once in a while to give me the room I need.

This is something to remember when you're looking for a new pair of motorcycle gloves.  Extra room in the throttle hand is important and can help prevent discomfort.  A perfect fit at the glove display may end up feeling too tight after 10 minutes on the throttle.

Conclusion
While the Fieldsheer Sonic gloves flow about as much air as any hot weather motorcycle riding glove that I've tried, I'm concerned about their ability to protect my hands when the time comes.  But they're comfortable, the price is right and they may be just the ticket on those super-hot southern days.

In the meantime, I'll keep looking for that perfect combination of air flow and protection.