I have the same question regarding my now almost 25-year-old Platinum Audio Solo speakers. For several years I've been thinking of replacing them with something new, but only because of their age. They still sound terrific.
The speakers were designed to be played with the grills on and I admit I never bothered to remove them until last year (you have to pry them off). The drivers look as if they were brand new.
I wish I knew the quality of the crossover parts, but I suspect the crossover was well built considering most of the rear panel of the speaker is a heat sink.