I sell new and used Toyo film holders, and post in the FS forum fairly often.
A few of the Toyo blue lettering holders have problems with the dark slides, which were not perfectly light-tight. I test such holders before selling them. The very latest holders have aluminum dark slides.
Toyo holders are extremely well-made and even the oldest holders I have (with metal slides and handles) are in proper working condition, with smooth movement of the slides. I'm not sure what Toyo does, but they never seem to bind. Occasionally, the bottom tape can show wear, and it can be replaced easily with bookbinder's tape.
Kumar