Ground Control Shoes/natural balance Q

[Kris Givens <givensb@prodigy.net>]

I am trying to find someone, anyone who has tried these shoes.  Here is
the site:

 http://www.plastichorseshoes.com/groundcontrol.html

They are very new from what I understand.  My questions on these are
this, and if any of you could be so kind to look at the site and let me
know what you think, even if you haven't seen/heard of these shoes I'd
greatly appreciate it:

1.  How far back are the nail holes sitting?  Is there the potential
problem that the nails holes are set back too deep and could run into
the white line?

2.  I like the sole protection.  However, it brings to mind the thought
that 'could pea size rocks or sand gravitate under that middle bar
causing problem?'

3.  The middle bar protecting the frog?  Could that cause coffin bone
soreness?

4.  Will these plastic shoes, like others, not be able to grab the nail
tightly hence causing hoof wall deterioration from a wiggly nail/shoe
combination?

It isn't that I'm picking the shoe apart.  I like what I see.  It is
just so new and I've not been able to find anyone who has tried these to
get their input.  They are pricey, but if all the problems above that
I've listed aren't an issue I think they might well be a nice shock
absorbtive, sole protective shoe for endurance, most importantly give me
a better jprotective shoe for the rocky conditions that I ride in than
what regular steel shoes offer.

What we are looking at using if not the Ground Control is the Natural
Balance shoe.  My farrier already has many clients who use this and is
well versed in the natural balance trim.  I told him I'd like aluminum
and he said that they won't wear as well in rocks.  My question for
anyone who is using Natural Balance is this:

If you ride in mostly rocky terrain, do you use the regular steel shoe
or aluminum?  Which is best?

Thanks in advance and please, no blasting me for going back to shoes by
those of you who knew we tried barefoot.  It just simply doesn't work
for our rocky terrain.

Kris