Old irons still good or new ones needed?

I am getting back into golf after not playing for 20+ years. I have FirstFlight irons (3-9, PW, SW) that date back to the early 1990's that I have had regripped and seem OK. When I get a solid strike they perform as I remember back in my younger years. Some of my golf buddies seem to think I should go for the new technology irons and that the old irons will hold back my game. However, I tend to think I really need to work mostly on my swing and that new irons would only be a marginal improvement. I would be interested in Tom's and the general Saguto Golf community's opinion on this topic. Thanks!