I'll be trying it during the next Free Rental weekend, too. I'm interested to see how 5.5 Forgiveness plays, given that every 3W I've ever used played like it had zero forgiveness despite what its forgiveness rating said.
I tried it during the Free Rentals this past weekend and bought it. So far, I love it. It is the first 3W I've had that just feels comfortable. And comfort gives you confidence. You feel like if you miss the ding, it will be OK.
I'll give 2 examples:
1. Congressional #6. I had 250yds to the back pin, wind right-to-left 12-14mph. Aimed my shot into the pond and hit about 4 lines late. Ball held its line, landed on the green, and hit the flagstick for a near double-eagle.
2. Merion #2 (multi-player game). Two of us had the same distance to the hole, about 237 yds up 37 ft. My opponent was using the L97 Callaway that goes 250 yds with med/high loft. His shot landed just past the left bunker and rolled onto the green 21 yds past the pin. My shot with the Mizuno landed on the fairway just short of the green and rolled onto the green 12 yds past the pin. Both shots with full backspin.
My thought is: For certain courses where you need more precision (eg. Wolf Creek and Olympic), the Mizuno is the better choice. For other courses where you need more distance (eg. Chambers Bay or Erin Hills), the 250 yd Callaways are a better choice.