Attaboy, Steve, good move. :-)
A bit of clarification on what I said above about no spin. The new precision you have now comes with a cost when you use the Callaways or Nikes with them. Spin increases the deviation when you miss the ding. Your results will quite often be wtf shots when you use a lot of spin and miss.
You can see this for yourself if you learn how to control those irons without spin, first. They choke well and you won't get hurt as bad during your learning period. Once you get a handle on them start small and smart with the spin. I see a lot of players addicted to backspin and use it all the time and wind up shooting themselves in the foot. Be careful and smart with spin, it really affects how those clubs perform.
By way of example, in a moderate wind going against you, full back spin will stand a shot up and shorten the carry thus knocking yardage off. 1/2 backspin will not shorten the carry as much and will stop the shot from rolling. With the wind, full backspin will carry the shot, usually farther than the rated distance, whereas 1/4-1/2 spin will control the roll at the end. This is the fun part of learning. :-)