Pings got a demo day coming up. I'll hit the new driver and look at the new irons but I don't see much difference on the irons with the G series from last year.
Driver...I'll check it out DC. The LSTec I had sounded awful which translates into it feeling lousy/hard. I don't think you'd gain enough yards between yours and this year's model...just better sound and feel. Your best best is to take your driver and hit it side by side with the 400 on a launch monitor. Bring your wrench and put your shaft in both heads.