Great post and good ideas. It never hurts to be prudent.
Gotta agree with you, the disclok is king - it doesn't grip the steering wheel so even if they smash the steering lock and even remove the ignition barrel they can not physically turn the steering wheel to move the car.The disk lock is the most effective one for your steering wheel I believe.
The bars that lock over your steering wheel are really easy to remove, they just saw your steering wheel and bend it to remove the lock, then it bends back into place, the locks that go from your handbrake to your gear stick get the same treatment, but they cut through the gear stick then (if they want) use a screwdriver to change gears.
I got told this about 4years ago when I went into a shop in Stoke-On-Trent to buy a steering wheel lock I bought the disk lock after the guy told me how easy it was.