It's only clear merit is in it's utter simplicity (*to a slight fault- no hood?) and feathery weight. If it had a decent hood and was $40 cheaper I might consider it as a SUL windshell thrown in my running pack, for those times when I'm soaked in sweat and stop at a high point to catch a view only, but not for running or hiking in. However, like you Mike, the Houdini gets it right and works just fine by me for an additional 2oz.
The 7d shell MHW uses is suspect, as any material of that denier, specifically in regard to breathability and durability. I realize this is a throw in the pack, "works in a pinch", type of shell, but for the price it just doesn't appear to cut it by my standards.
Less expensive yet comparable alternatives:
Montane Slipstream GL- 2.3oz
Montane Litespeed or Featherlite smock ~3-4oz.
Montbell Tachyon Pullover or Jacket ~2-3oz.
I found the Tachyon with it's 7D shell to be acceptable for use on the move, but not for very long. I cannot see the Ghost Whisperer performing better than the Tachyon.