Warranty Week article from 2004
Its pretty interesting to see how many of these firms with 20 year warranties didn't make it 5 more years as a company before folding, or being acquired by other firms. Most of these firms that were bought out aren't honoring the warranties offered at the time of sale, which could be the #1 reason to avoid modular equipment altogether.
Even www.skatepark.org is under different ownership than the writing of this article. However, the message still rings true today: