PGA Tour player Mark Wilson won the 2012 Bob Hope Humana Classic. And he had the new Ping i20 Irons in the bag. The i20 is for players as good as Mark Wilson all the way to your average mid-handicapper.
The cheap i20 irons pack in a lot of new design tweaks from previous i-series models. The biggest visual change from previous i-series irons is the "toaster" style tuning port in the cavity. According to Marty and PING, the i20s have a couple more degrees of bounce with the addition of a little smaller camber radius from the front to back. This makes it more rounded from front to back, it also helps the playability of the leading edge.
As was the case with the i15's, the i20s are noticeably longer heel to toe in the long irons, gradually decreasing in size to the short irons and wedges. This time around, PING made the top rail thicker in the long irons transitioning towards a thinner top line in the 7-W, dramatically increasing the MOI where golfers need it most.
If you've gotten a chance to see the cheap anser forged irons, the i20s are very similar at address, as well with the toe to heel spacing. I find I like this look better, less distractions and makes it easier to line shots up. Obviously more offset than some "tour" irons out there but for a forgiving cavity back, the 6 iron-W in the i20s look great.
As with most PING irons, the i20 has a number stamped on the high toe that let's you know at address that you have the right club, and the bottom groove is filled with white paint to aid in alignment.