I have one but I find a standard reflector with a gridpot is much more versatile. You can feather the hotspot and change the hotspot size with grids. Not much adjustability or control with the shovel.
The mostly-uncontrollable spill, inability to gel effectively, and most importantly the minor rippling that appears in seamless when the shovel is placed near the paper (the harsh angle that the light skims across the seamless creates subtle shadows/waves in seamless)
The reflector w/grid hits the paper head-on (mostly) thus lessening the appearance of ripples.
On the plus side of the shovel, the shovel will allow you to light up a background in much tighter quarters, requiring only 2 feet from light to background to create a background glow (see above for potential caveats, though)