Touch-screen speaking, I'd prefer the DS. From the day it came out it felt to me like the perfect point-and-click platform... Touchscreen + a screen for maps or the inventory (and you'd switch screen to click on the inventory).
I've been surprised that not more adventure games came out for the DS. I know some did, but I was expecting more of them to.
I'm sure people would buy a DS game that would contain old adventure games for instance.
Anyways. I do think a touchscreen, if we're talking about point and click, is better than a mouse. A mouse is just a way to do it before touchscreens were invented.
But now TTG is moving away from point and click so I'm not sure.