Do a System.print() and you will see it is constantly running. That's why things are so 'zippy' as you point out.
With regard to testing things in the simulator, please keep in mind that when testing on simulator, you are using the power of the Main CPU and Graphics CPU. When testing on the Pronto, you are using the "Real Thing".
I have started to use PEPV2 simulator for some things but find that my older way of working with the Docking Station Mod (See
www.the-gordons.net for Pronto Debugging) still works best for me as my configurations still are based in PEPV1 but capable of being loaded into PEPV2 (I've already done the pre-work for My Database).