I have a pair of Heresy II's I purchased brand new back in the day. They are still in great condition and sound pretty damn good.
The good news is the woofer surrounds on these are not foam so they should still be in tact. The only area to look at updating due to aging is the crossovers. The capacitors can change values over time affecting the crossover points.
If you are so inclined, I'd also recommend replacing the stock phenolic diaphragms with new titanium diaphragms.
These two updates were huge improvements for me. Google Bob Crites - they offer both upgrades.
