There is no big deal. The CI issue/debate has been divided into 2 camps.
Camp 1 says you dont need the CI and all adjustment can be done using the VPI arm.
Camp 2 says the CI is needed to properly dial in correct azimuth and VTF.
The answer is both are correct. You dont need the CI to dial in azimuth and VTF but the CI may allow for a finer level of adjustment for azimuth and VTF. Also, some just prefer to use the CI.
Camp 1 says you dont need the CI and all adjustment can be done using the VPI arm.
Camp 2 says the CI is needed to properly dial in correct azimuth and VTF.
The answer is both are correct. You dont need the CI to dial in azimuth and VTF but the CI may allow for a finer level of adjustment for azimuth and VTF. Also, some just prefer to use the CI.