I rented them. I've been playing with level 32 R11 irons, so I can't tell you how they compare with anything at the top of the food chain, but here's what I've noticed
At Congressional #10, par 3 over water - 208 yds, 4mph left to right wind.
Shot: 205 yd 4 iron with full backspin
Hit: a couple of pixels late, but very close to ding
Result: landed a 209 and stuck right of the flag - as expected
At Bethpage #3, par 3, 209 yds, pin down 11', 3mph headwind - very similar shot to Congressional 10 and this hole always plays short
Shot: 205 yd 4 iron with full backspin
Hit: Ding
Result: landed at 197 (surprised by this) on line with the pin
At Bethpage #8, par 3, 183 yds, pin down a bunch (20' ?), 4mph tailwind
Shot: 190 yd 5 iron, full backspin (I know this is too much club, but curious)
Hit: Ding
Result: 194 yds on line with the pin
At Bethpage #9, approach from 170 yds, pin up 11', 3 mph right to left (slight headwind). I can never hold this green with the R11 irons.
Shot: 175 yd 6 iron, full backspin
Hit: Ding
Result: landed in the front fringe at 163 yds and rolled to 166 yds a little left of the pin
In two rounds, the irons behaved about like I'd expect for the price. Lots of stopping power, high ball flight, goes where you aim it with decent forgiveness on slight miss hits. I didn't miss the ding very wildly, so I don't know how they would react to that.
There are some holes where I like to run long iron shots with no spin (the approaches on Congressional 11 and 14) and I was curious to see how the higher trajectory would translate into roll. Surprisingly, I got much more bump and run roll than I expected on both shots.
These seem like very versatile irons that are capable of many different kinds of shots, not just backspinny long iron shots. It would take some time to get the distances dialed in, but I think they're definitely an improvement over any clubs beneath them.
I won't buy them until I get a chance to try out the rocketblades though.