I own both master iron sets (G10 and Preferred) and must say I love them both, in conjunction with G13-S balls. I have yet to compare them thoroughly using GI-SD balls, but I venture the guess that again, in all settings, these two sets are solid performers.
Of course, BolloxinBruges is a better player than I ever will be, but I sincerely wonder if he gave the Taylor Made irons as fair a shake as the G10. True, the G10 (210-115Y) has a wider span than the Preferred (210-122y),but does a 7 yard difference really matter? I think not.