Mix both worlds. Like I have learned from a very investigative YT video. He tested and measured dishwashing in many different ways, and came to the result that a) tablet in that place in the door is the thing to do, but also b) a bit of dishwasher powder into the little compartment right next to it under the flap. This is for the first cleaning stage, and since we use this trick, our dishwasher runtime (which is dynamically depending on cleanlyness of the dishes) has gone down by about 20 minutes.