The Rapture V2's are the best in terms of both having slow meters and having high forgiveness. The R9's have similar forgiveness, but faster meter speeds. You do get slightly more precision with the R9's, but I'd guess that the V2's would be the better option if you are having troubles "dinging" your shots.
If you can do well with your R9 driver, though, then I would guess that you could hit the R9 irons. If you're having trouble controlling the driver, go for the V2's.