Quick TM or charge TM ?
Which do you value more? I would say quick TM is better because it guarantees you what you want.
Answers
I would say its fairly even overall.
But yes quick move is the more safer option obviously as you cant get the wrong roll, meaning charge TM's will be the one we need most of in the long run most likely.
but overall gameplay impact may come more from the charge move, or both equally...depending on the move/pokemon however. Some quick attacks are just spammed with the idea of gaining energy to blast the power charge move such as solar beam.
To get that perfect moveset...both moves have to be right, (depending if you need to roll both or already have one ideal move) so in some ways they are both as important as each other, it just depends on what you need. Its just riskier to roll the charge move with the way it works.
I've used two charge TMs and in both cases I knew I'd get a move that I'd be okay with.
I used one on a Hyper Beam Dragonite having a slight preference for Hurricane, since I already had a Dragonite with DT/O, but I got Outrage and I'm fine with that.
I used another on a Fire Blast Tyranitar. Again, I had a slight preference for Crunch but I wasn't at all disappointed when it rolled Stone Edge.