Well... Doesn't look like anyone else will post for ya. So, in the short time iv had chameleons iv found replicating the wild is your best option. Misting sprays so finely they can't focus on the droplets. The rain system makes it easier for them to see. Mine love the rain droplets.
This is my personal opinion, and I think this is what you're going to get with a question like it. It sort of comes down to preference.
I have a mistking but I've also replicated cheap "rain" just by putting a large jug of water on the cage with multiple little holes so it drips from 10 places and looks sort of like rain. Obviously pretty crude, but it works lol All of mine seem to love their mistkings and several of them memorize the misting routine and stand facing the nozzle with their mouths open when it goes off. They seem to love the fine mist. But when I do drops or drippers, they also like to drink off the leaves, so I think either method is probably fine. If you prefer rain then by all means, I don't see a reason to not do it.
(edit) At the same time, I always see plenty of droplets when I mist, but that's because I mist for 5, 10, or 20 minutes at a time, so there's a LOT of water going through my nozzles. And by the end of it my cages are soaked and there is plenty of drinking surface. I think that regardless of what you do, I'm partial to long showers. It usually doesn't rain for 30 seconds at a time in the wild, so I figure a longer shower is better for them.
i tend to go mist for me..my chams arent too into heavey droplets of chilly water hitting them and are more tolerant of a fine cloud like mist..and as it builds up it causes "rain" droplets to start falling...so it seems to be an all in one for me...