I had linked brakes on a CBR1000 and again on a Blackbird. The system helped to give balanced braking.
each calliper had an extra piston. When applying the front brake an additional master cylinder mounted to the fork leg would be operated when the front suspension depressed, in turn operating one piston in the rear calliper. When using the rear brake, one piston in each front calliper would be operated. This set up in effect gave two separate braking systems.
The suspension needed to compress a fair way before the rear brake was applied, this meant that a compression caused by normal suspension movement or throttle roll off did not operate the rear brake.
Its fair to say that on a sports bike the system was a no no, especially when rear trailing braking, but on a sports tourer style bike the system was good. I personally liked the system, but its not to everyone's taste,
The system got bad press from journalists because they seemed to test the bikes like they would test a sports bike.