They've gone through some changes of ownership and changed horrendously in the process. At one time, though, they were the best source for a great variety of roses. Jackson & Perkins were good too, but they concentrated mainly on their own roses. Wayside used to send out a rose catalog that was incredibly impressive. I still have the ones from 2001 and 2003. Each has 47 pages, with as many as 6 or 7 roses on each page. Their plants were grafted beautifully and never failed to grow. I still have all of the Wayside roses I ordered in those days. The prices were great and they offered package deals.
In 2001, for example, they offered "Wayside's Classic English Rose Collection" -- 1 each of William Shakespeare, Charlotte, English Garden, Gertrude Jekyll, and Fair Bianca for a total price of $39.95 for all 5 plants.
Wayside's the first mail-order source I ever saw selling Austins and Buck roses.