Even better than SPICE is an actual breadboard. With an actual MPF102 and using a 3.9k in parallel with a 180K resistor (giving me an actual value of 3.77k according to my multimeter) I get 2.500 volts on the dot.
As for temperature stability, I only saw a change of 1mV when I touched an ice cube to the top of the FET.
I think it's good enough for my purposes.
EDIT: I spoke too soon. I had 2.5V at the output when I fed the circuit with 5V. When I feed it with 9V, I get 2.532V. Not exactly self regulating voltage wise, and not what I got with Spice...