When it comes to talking about the Ping G series irons (and other game improvement irons) I think it is wrong to talk about handicap ranges for who they may appeal to.
Ping G20 Irons I think you should talk more about how they would benefit a persons game and this is independant of handicap.I play off around 7 handicap but my ball striking and GIR was an area that I wanted to improve to give myself more birdie chances and to not have to always rely on my short game.
When i purchased my G15′s (my first ever Pings) about 6 months ago it was with this in mind.
TaylorMade R11s Driver I keep stats and in that time I am averaging 1 more GIR per round even though this has included a time of getting the feel for the new clubs. My message is forget about the looks, naming, target group, what others say, etc, just get clubs that will help you in areas of your game that need help.