Looks like Toyota is firmly entrenched with the "soccer moms" with this option: Vehicle Stability Control (VSC) with Traction Control (TRAC), Daytime Running Lights (DRL) and automatic limited-slip differential (with fog lamps on V6 models)
To answer your question, I don't think there's any difference in the LSD's as to their operation. I think the TRAC and the LSD will operate separately from each other. I think the VSC/TRAC option is probably a nice option to have if you don't go off road much, but the first time the VSC and TRAC kicks in, you'll think your motor or something up front is about to "blow". Takes a little time to get use to "those" noises.