Older sets with high playability absolutely can still be played. The original 845 was a Game Improvement design and very popular. The 845U (2003) Ralph actually designed and was an Ultra Game Improvement design. Not with these two designs, but there can be some trade-offs not related to the pure playability you should consider when looking at playing with older model irons. You definitely want to look at the sole angle and radius. Some older designs tended to have less forgiving sole designs (flatter soles with less bounce). More noticeably today, would be the differences in the lofts. Today’s lofts, in some cases, are much stronger than many older models, so beware that you might not hit that old 6 iron as far as you would a new one and the only reason may be is the loft. The Ping Eye 2 is still, I think, Pings best selling model. In short, the MPF can be a very useful tool in looking at the playability (based on the mass and dimensional characteristics of the design) of older designs. However, you need to also look at the sole design and be aware of the loft differences that can occur from older models to today’s models.