We don't lose much, most of time, so little it doesn't matter. I think some dinghys were designed with towing in mind, and some weren't. Inflatables are huge drags compared to our dinghy. I know this because I have two friends with the same dinghy(9'6" Joel White Nutshell Pram) and inflatables(soft and RIBS) and they have dragged them for miles on 30 to 40 foot boats(the reason for 2, young kids). You get a real sense of the drag comparison adjusting the two.

I consider the dinghy painter the last line to trim and always adjust so I feel the dinghy come up on the stern wave, trim bow down a bit, and glide. This requires adjustment constantly if you want to get the least amount of drag.

Here in Maine, everybody tows a dinghy except offshore so there's a lot of concern about what tows well and what doesn't. Our dinghy is a huge compromise as they all are, but towing was a primary design concern and it's very good at that. I've haven't had a mishap two times up and down the east coast Canada to the Exumas.