For someone without instrument training, I don't think the WAAS would make much difference over a non-WAAS 430/530 for survival in a weather emergency. It generally takes IR trainees 5-10 ILS's before they're tracking GS well, so having the vertical guidance needle probably won't make that much difference on their first experience with GS, no less their first experience with GS in the weather, and without prior tutelage. Heck, a good portion of my trainees can't remember whether an "up" needle means "fly up" or "you're above the GS so fly down" on their first attempt. Add the stress of a weather emergency and zero training, and they might do better without it just flying altitudes.