Most procs give you an amount of a stat for a duration. For instance, Volcanic Potion grants a buff called Volcanic Power which gives 1200 Int for 25 seconds. Moonwell Chalice gives an amount of Mastery for 12 seconds. You get the idea. So SPDT tells you to refresh your dots with procs. 20 seconds into a fight, procs feel random with no real way to discern if a proc is a DPS upgrade. What I've done is use HowToPriest.com BiS scaling numbers to convert a buff to it's Int equivalency and created what I refer to as a "buff score". As of 1.0c all of this data is configurable in the options panel under Blizzard's Interface-AddOns tab. There are two bufftables. One that the user has to fill depending on his trinkets and upgraded versions, which can be managed via the ingame menu. The other bufftable is hidden and i call it class/standard buff table.