I've been lurking a here a while, and this is a timely subject to chime in on as it's something I've been thinking about recently.
A couple of weeks back I came across some Menghai 7572 from the early 80's. It had been stored in China for a while, and spent most of the last 10 years or so here in Malaysia. High humidity conditions are normal here, and I know for a fact the beengs were well ventilated over the years. The 7572 is a shu using a variety of leaf grades.
The 'shu' smell, or 'cooked' aroma is all but absent from the dry cake, and big leaves were visible from both sides of the cake. The dug out segment also showed potential. I was amazed at the condition of the cake.
Two rinses, and a lovely deep burgundy broth poured forth from the pot. The body was substantial, and the flavours deep and earthy, with a prolonged finish. Time had certainly done it's work, with the tea exhibiting an impressive endurance.
The experience demonstrated to me, for the first time, how shu can age, as previously I'd been wholly obsessed with aged sheng. And I concluded that it had aged pretty well!!
In order to further explore this tea, I've dismantled half the beeng into a clay container, to approximately 2/3rds full. The lid is left partially open, and by aerating the tea in this way, I hope to open it up further.
Conversations with more senior tea drinkers always yielded similar opinions, in that a good shu will age and develop to provide years of drinking pleasure. Patience will improve, as will flavour and smoothness. We're not too concerned in these parts when it comes to dry or wet stored, for as long as light is kept away and ventilation is available, the rest should take care of itself.
Pu Erh aging in SE Asia is generally speedier than in the Northern Hemisphere due to constant humidity and relatively higher ambient temperatures, so even a 5 old tea here may display characteristics of a 15 year old tea kept elsewhere.