Out of curiosity does anyone know whether it would be more beneficial to have more switches with less terminals on each leading to your main switch OR load up each switch fully before having any terminals added onto another switch?
Additional switches, whether they are full or not, will provide MORE paths to your upstream switch and thereby increase performance for users distributed across them. Many things will be a factor here as far as performance. Let's say your root/core switch is completely 1Gb, and to each downstream switch you provide a single link. Even though downstream each of those users is connected at 1Gb they are bottlenecked back to the core at the uplink. Now if you spread those connections out over multiple uplinks (read more switches) or by using link aggregation, you also increase performance. Really you need to define your requirements, but a bottom line answer is that "the more uplinks the better" regardless of how many switches you have or their port density.