Surely you have room for one of each!

Wow....I've been installing these things for years and have never asked or been asked that question. Watering can or rain head showers can put out no more flow than the valve that serves them allows. Most valves are flow restricted...water saving as required by the building codes. So some of the really big rain heads are sort of more drizzle heads. Same is true of handhelds, except with their smaller head, they give a bit more pressure... That said, we test them to make sure they function...but I don't get in under them, so all my experience is more visual than kinesthetic.

I prefer the versatility of a hand held. I've heard complaints about rain showers looking great but not really being that practical. I have no experience with them, however, whereas I have found hand helds have SO many uses (good for the elderly, kids, and even dogs)

We have both in a basement bathroom we recently finished. Rain head up high and centred and then the hand held on slider on vertical bar - for height adjustment. Lots of room for both because the rain head has a longer extension from the wall.
Rain shower head for fun experience, hand held (either really handheld or in its mounting) for doing the real washing and rinsing.