Cayugad, I've got a stash of T7 from a Wallyworld deal last year (2004 actually)and a stash of Pyro P from a prior purchase (maybe 2002 - am running low on Pyro P). Both powders are kept in the same storage box in the same closet in my house. Been noticing the T7 is a little erratic but the Pyro P is as good as ever. Recently opened two new bottles of each and, based upon my own limited experience, would have to say the Pyro is holding upmuch better.

And dangit! I've still got several pounds of the T7 left!