Hi folks,
I am new here, and this is my first post... Or reply to post more accurately. I am just getting into bullet casting and this lead pot topic caught my eye. 
I feel I should warn you that the PID control on a lead pot as marketed is a little less than accurate. A PID controller does provide a signal output in response to error from set point. The problem is that the heater control is a digital on/off device. So much like changing the power level on a microwave oven, you are simply rapidly turning on and off the heating element to simulate an analog signal. The problem I see with this is that the relay used to switch on and off the element will burn out relatively quickly compared to a standard themostat with a deadband while will drift the temperature +/- from set point. The way to truly provide PID control would be to have an analog control device such as a SCR heating element. Of course this would be more expensive, which is no doubt why they don't do it. At any rate, just a cautionary tale of what I predict will happen over time with the built in PID control strategy.... Relays can and do give up after so many thousand cycles.

A SSR will definitely help with the longevity over a mechanical relay; if that's what they are using. Not ever seeing a wiring schematic, I wouldn't know. But I would echo your concern regarding the heat affecting the controller and the SSR.

Sorry; I guess I am not exactly trying to make a point. It just irritates me that it's really pseudo PID control using a digital relay; SSR or otherwise. Tighter deadband? Yes, but not really a true PID control.

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Do not most folks that setup a PID controller use a zero-crossing solid state relay?  (Good for LOOONG time)

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Perhaps I am over emphasizing the issue. Indeed, if most folks are controlling their pots using an external PID controller and. SSR, then beat won't be an issue and you're right... It will last a long time. 
In the case of the products made off the shelf, forgive me... I am used to companies cutting corners all too often it seems, which in this case would be a mechanical relay. If the products being sold are equipped with SSR's, so long as the heat sinks are properly designed, the end result will be "close enough for the girls I go out with" as my father used to say.

[/quote]Do not most folks that setup a PID controller use a zero-crossing solid state relay?  (Good for LOOONG time) [/quote]

Yes, you are correct.
Wayne