However as several of the comments bring up, the idea of putting spec information directly on drawings or in schedules tends to break down when addressing public works who require multiple bids and true performance specifications with alternates for all products. Large complex projects have similar obstacles.
That said, in my own work, I find a hybrid approach best. For those products and specifications that require only performance information, a traditional specification is best, however for proprietary products or materials that are integral to the design I like to use a schedule(s) that list out the information in a concise way.