Engine braking is no longer required on modern cars, and is no longer taught to beginers.
I suggest that any car where you feel engine braking is needed does not give the driver adequate confidence in the OEM brake set up (an issue with Mini's, granted), however, with the advances of brake setup, electronic stability controls, disk and pad materials, chassis dynamics, tyre dynamics, engine management programs etc etc etc, engine braking is a mere habit that is admittedly hard to break.
Like any bad habit, you know you really shouldnt.
The truth be said, in a modern car, using engine braking techniques actually increases the periods of time when you are not 100% in control of a cars actions.
Oh, and anyone whose tried down shifting on a race prepped car with plenty of power through the rear wheels will be able to tell you what the crash barrier looks like....
you can get away with it on many occasions, but theres alwats one when you get that huge 'torque bite' that throws you in a different direction than you intended to take...