Go with the incendiary ones every time - they last practically forever, even when not stored in ideal conditions, i.e., rolling around in your trunk, and they WILL function reliably when it is really cold or snowing or nasty, whereas the electronic ones may not, especially in sub-zero weather.
I would second the motion of getting the first flare lit and then using it to light the rest of the flares, much easier than whacking away at the igniter cap over and over. But, I have also learned to keep a lighter in the glove box as a backup ignition source.