FCeng84 thanks for your post, although I noticed it a little bit late!
I was aware of the U part of the C*, but I had read something about the pitch damping mode, too, I don't know where (not in the FCOM I believe). I wondered if there were variable forces in the control column for the trimming, but seems not.
So, if the B777 is as you say, and I'm sure it is, when the pilot uses the trim switches to change the reference speed after a change in the equilibrium, he has to release the control column until it is back in neutral. Is that right?
I mean, in a conventional airplane, if you gently pulled the yoke and kept it close to your belly, and let the speed drop, the pitch stabilized shortly after and the airplane reached a new equilibrium at a slower speed, and it required a given force to maintain that situation. Then, with the pitch trim switches you could relieve the force required to keep the column right there, until that force became zero. The yoke remained there thereafter, close to your belly. As I understand it, in the B777, however, you have to ease back the column to neutral as you trim (it is more or less they way that MS FS pilots trim the airlplanes with those unrealistic controls).
In a way, Boeing and Airbus controls are so similar, specially in maneuvers not involving speed changes, with the A/THR in SPEED mode. Pull or push and release to neutral just as the flight path becomes the desired path. Easy!
The U part o the control law, seems to me, is there just to make the pilot feel a bit more like in a conventional airplane, in spite it is not. Far from it. I mean, imitating conventional takes more technology than just embracing innovation. Boeing system may seem simpler to pilots (or so they say, them Boeing pilots) but it is probably more sophisticated than Airbus.