IMHO, I think a lot of it depends on where you're at right now. If you can hit the ball straight, consistantly make solid contact, are comfortable with long irons, and have been able to translate driving range performance to the course, I'd say you're ready for a high quality iron you can grow with. If not, I'd say spend the money on some lessons from a reputable PGA pro, balls at the driving range, and practice rounds at the local course.
Of course if you have spare $$ to burn, why not spend it on a nice set of irons. They'll last a long time and as an added bonus if you go forged, I doubt there will be any revolutionary advances in technology such as in drivers.
For a high handicapper looking to lower their scores, I'd suggest a forged cavity back or one of the newer forged muscle/cavity back combo sets. Models to check out include Titleist 690 CB
, Nike Forged Pro Combo
, Mizuno MX-30
, Ben Hogan Apex FXT Forged Combo
. In a cast blade style cavity back with a nice thin topline look at PING S59
For me, moving to forged blades really helped me improve my ball striking simply because there's no two ways hit them. You either do it correctly or pay a pretty severe penalty in accuracy and distance.
Forged cavity backs would be a nice way to go since they provide some forgiveness but still give you good feedback on off center hits. As you get better they will definatley allow you to learn how to work the ball since most of them are identical to muscle back models with different weighting.
I really like the idea of the new forged combo sets with muscle backs in PW-7I, and cavity backs in 6I-3I. Even most higher handicapers should be able to accurately hit muscle backs in the lower irons since their high lofts reduce side spin. Having forged cavity backs in the longer irons allows for some forgiveness and the lower center of gravity helps in getting the ball nice and high in the air.
Whatever you decide don't rush into it or get pressured into a deal. Hit a lot of different models and see which one suits your game best. Also find a place willing to fit you, it's vital to your progressing in the sport.
Just my $.02 hope it helps.