The 1975 Pontet-Canet has been stored by me since shortly after release. Early on, it was very acid and tannic, and was no joy to drink.
Now the wine is smooth enough to drink with food, although it still has much acid and still some very dry tannin. The fruit is typical Pauillac, but rather restrained. The finish is somewhat short. Although it could become a bit more smooth with more age, I do not think it has enough fruit to justify keeping longer. I think it is going to dry out over the next several years. It is not a bad wine, especially with food, but one can think of many better examples, even from 1975.
Pontet-Canet is a large estate, and has a good location next to Mouton. However most of their wines from the 60's and 70's were not very attractive. I have tasted the 1961, and it was an outstanding wine. I hear that this estate improved in the 90's, but I have not tasted more recent vintages.