I used the foundry provided models (BSIM3 and BJT) but result from the two simulators are different by about 110mV on a bandgap (Brokaw cell).
Temp SPECTRE HSPICE
-40C  1.087V    1.197V
The BG over temp curve looks different as well. Models were checked by the foundry modeling group. The foundry golden simulator is SPECTRE. So the HSPICE model is derivative of SPECTRE. But I tend to believe HSPICE because it is closer to 1.205V at low temp.