I say to newbies to go to a remote
bay with no one around and practice using the mooring float as a reference. Practice and practice to learn how your boat acts and reacts. Each and everyone is different. And it is not just because of the keel. Other influences like engine
power/prop size. Angle of prop shaft. Rudder design and size. Steering
. The list goes on and on.
If anything a larger keel will be a little more forgiving. Small keels and flat bottoms give little sideways support in cross winds. A full keel just gives you that fraction more time.
No boat backs down well when you are trying to turn at the same time. A large keel is no exception and in fact a little worse. But that can be used to a big advantage. When you want to turn in a tight spot, keep the helm
turned in the direction you want to go if you were moving forward. Leave it there. Now shift from fwd and rev with the gears to control speed. When you apply rev, the boat will not turn easily. When you select fwd, the boat will turn much easier. So select fwd and get the boat turning, select rev and check the fwd motion. The boat will slowly turn on it's own centre and within it's own length. Depending on prop walk, it will do this one way better than the other. So practice to see which is better. That prop walk can be an advantage once you get to know how to use it. Using a dock
line to spring yourself off or on to a dock using the prop walk can be a real asset. Wrong side, and it can be a complete curse, so you have to do things differently.
Another thing to learn is the distance it takes to stop the boat. You need forward motion to control direction, so you need to enter a birth with reasonable speed, but you need to know when to apply reverse and how much engine RPM
and so on.
The reason a boat does not back and turn well, is that the turning effort is created by water
moving over the rudder, which is a wing. So you have to have sufficient water
speed in reverse to have it apply enough force to turn the boat. If you do get enough speed, the forces on the rudder are huge and you can cause damage. The wing is in reverse, so it is not efficient and the effort against the rudder is huge and applied in a way the rudder is not designed to take. When in forward, the rudder now has the water from the prop washing
over it. It is the prop wash that acts on the rudder that turns the boat when the boat is not moving forward to generate it's on effort. So hence the boat will turn in forward gear
and not in reverse. So practice where no one is watching and learn all the traits of your boat.