Thoughts on replacing caps in 30 year old speakers

There is a capacitor review on humblehomadehifi.com that you may find interesting.  He tested a bunch of them and wrote his impression.  I thought about replacing the capacitors in my Infinity Renaissance 90 speakers a few years back but never seemed to have the ambition or time.  Evidently Infinity tested each capacitor installed and if it wasn't up to spec they would add, delete or change until it read proper.  Two of the same crossovers may have different capacitors in them.  I figured there was more of a chance of me messing it up that fixing anything.
Good luck , John

there is a lengthy and interesting discussion of this by Alan Shaw on the Harbeth users group web page

Shaw is the owner/designer of Harbeth 

That harbeth forum is one i had read . what was the final thought on the polyropylene caps lifetime ?

it's a long, complicated response.  Harbeth's do not need new caps, other speakers might...I think that was his conclusion