From looking at the few videos that have been posted so far it looks like if you imagine the group head is a clock face, the pump kicks on at around 4:30 at 0 bar, and then by around 7:00 it is already at 9 bar.

My impression is that :

1. This doesn't seem like enough movement for it to be a gradual and easily controllable path from 0 - 9 bar (or whatever you choose for max pressure)

2. People in the videos using it seem to be tensing their forearms to achieve the required micro-movement, and doing almost a back and forward motion to increase pressure where they try and increase a bit by pushing with the heel of their hand, realize that pump pressure is now higher than intended, and use their fingers to pull the paddle back which yeah doesn't seem super relaxing to do a few times in a row.

Is is much better in practice for those that have had a play already, or does the paddle travel ideally need to be longer?

I have used the new paddles with the conical valves on four separate occasions now. At first, I wished the travel of the paddle was a bit longer, but with each shot I pulled, I realized that the travel is just right. There is resistance when moving the paddle. Enough resistance that if one's palm wasn't resting/braced against the group cap, it would be very difficult to replicate a pull from one shot to the next. If the travel of the paddle was longer, then a palm wouldn't be able stay in one place while moving the paddle from right to left.

Of course, if you still want a longer travel, then that's easily accomplished with an extra long paddle attachment (=larger radius).

I would imagine that you would want the paddle to be logarithmic tapered. So the majority of the travel be between 0-3 or 0-4 bar and the last 15 degrees or so to be the 4-max pressure. If it is linear, it would seem hard to control.

Since you are trying to do gradual ramp up. For decay it would ideally be the opposite taper - but that would be hard to do....

I've been using the new MP GS/3 for a few months now and I've found that the paddle movement has plenty of range and I wouldn't want more as that would be cumbersome to use. I.E. too much rotation required.

The paddle was also stiff for the first few weeks of use and has settled in nicely to move, but have a ample amount of resistance for feedback on the movement.

As for repeatability, well, that's more subjective. I'm consistently able to hit the pressure range I want for pre infusion using the brew group manometer. Since that feedback is analog, and the pressure is measured by 1 Bar major increments, the actual pressure is open to interpretation. Therefore, I can't claim that every shot is as consistent as what a digital programmable method would provide. So it all comes back to what level of control your looking for.

I'm very happy with the quality of shots I'm getting from this machine, and the consistency is there cup to cup for my palate. I'm also not running a cafe, or catering, and I'm the only 'barista' for my machine.