I just got my HiPro in yesterday.  I've only typed on it for about 15 min so far.  This is a very unique keyboard.  Initial impressions of the HiPro are mixed for the moment.  But i'ts growing on me fast.  One thing in particular that I love about this keyboard is the way the number row catches your finger.  I tend to fat finger the "underscore" in particular and often get "+" to go with it.  The upward curvature and more narrow key target have solved that problem right away.  I also love the way the backspace catches your pinky.  Also, the scoops.  this has no nipples on the F and J, but rather very exadurated scoops on "S, D, F" and "J, K, L".  It really just grabs your hands and forces them to the home row.  I have never had trouble with this in the past, but this really will make sure that their is no issue.  My only complaint at the moment is that it's a little louder than I would have liked.  My neighbors at work are sooooooo picky about noise at work.  I'm sure they would complain about it.  Heck, they even complain when I get going fast on a rubber dome.
I'll likely post a review comparing the HiPro, to 87U (silenced), and 87U 55g later.