I saw them and they didn't look bad. If u have G400, there really isn't much difference. If u listen to a Ping ad though you'd think there was a huge difference.
If I was a g or g30 guy looking for irons, I'd spend the extra money and get the 410 over the 400. Blade length is better, top line is nice. Offset is a bit less, the wedges still take some getting used to looking at though.
As far as the cavities go... These are growing on me. I wasn't a fan of the g400 and I hated the G.
I haven't hit them yet. So far as much as I want to embrace the new iron tech...I just can't...the sound and feel is awful. The g700 and i500 are awful to me. I really want to see how the 410 is. The 400 was better than either the 700 or 500. The TM p790 is ok...at first I hated it but it's like butter compared to the Ping i500 and g700.