I usually use Lutron Diva dimmers for ballasted fixtures. I find I'm trying to lay my hands on the $80 one used exclusively on electronic ballasts more often than the model used in magnetic ballasts. I'm guessing the main difference between the two is the frequency they are tuned for.
I have had a customer hire me to remove a pair of Lutron Smart dimmers (incandescent) because the RF they generated interfered with their habit of listening to AM radio in the kitchen.
