No, they are significantly different because a multi-rotor does not fly. So when the multi wants to brake, it tips up. Which reduces the vertical thrust vector and it wants to fall out of the sky. So it surges its motors to provide the horizontal vector to brake, and the additional vertical vector to hold altitude.
The heli or plane is a true flying machine. Tip it up in flight and instead of wanting to fall out of the sky it wants to go up. Unlike a multi both can convert kinetic energy in speed into altitude. With a helicopter you don't dump collective pitch to brake. Go to your local medical facility and watch a heli come in for a landing. It don't come screaming in at 165 kts and suddenly go into a 30 degree nose up and dump collective. That will make it crash. When it leaves translational lift (like stalling the wing on an airplane), that, combined with dumping collective, will cause it to go into Vortex Ring State and settle with power. Instead, just like an airplane it does an approach where it bleeds off speed and gradually increases collective pitch as it leaves translational lift and goes into hover. If you do the dumping off collective thing with a lightly loaded heli, like most UAV's are compared to full size because you flared it too much, it results in the "brick wall stop". Which is highly undesirable for UAV operation. Caused by the sudden surge in collective pitch as it increases again after leaving translational lift. But the result is a lot more dramatic than a multi, as witnessed by the capabilities of helicopters in 3D flight.
It's very hard to explain unless you have experience flying one. One of the things a new heli pilot learns is how to control speed. I think you termed it "slippery", but a helicopter does not like to hover. They like to fly. They only have the capability to hover. But where they really shine is in flight in translational lift. The amount of braking we can use is all based on the speed so when it leaves translational lift the collective pitch is smoothly increased to hover configuration so the heli doesn't "recoil" to recover from falling out of the sky because it suddenly lost two sources of lift.
I don't know how to get this right for New Loiter.
Where it's going to matter is in Auto flight. As it is right now, there is no way I can use the WPNAV_ACCEL values needed to hit waypoints to bring a helicopter to a stop in Auto from a 27 m/s flight speed. I have to use Channel 6 to set WPNAV_SPEED on-the-fly as it's coming in on its approach to gradually bleed off speed so it can transition to hover. Or sometimes I "cheat" by setting two waypoints close together at different altitudes so it forces the heli to slow smoothly to make the altitude target at the next waypoint. And then I will "cheat" again and switch to Stabilize so I got control of it before it hits the final waypoint and attempts to do it's autonomous braking thing, which is not very smooth.
I don't know how much of the Loiter changes carry over to Auto flight, but that's where it's going to be critical to have it right. The current Auto flight controller is not ideal, but is functional once you learn how to work around its shortcomings. We have to be careful to not introduce more shortcomings into the Auto flight functionality because that is the primary use of the software for the great majority of our users.