A brake disc’s face type (slot / groove pattern) is one of those changes and can influence many braking characteristics. 

Some of them are: 

Initial response (bite)

Control and modulation

Release 

Pad wear 

Disc wear.

There are also many variables which are considered when engineering a brake disc face type. Changing some of these variables can drastically influence the overall performance of the brake disc. Some (of the many) variables which are taken into consideration for brake disc slot design are:

Slot depth 

Slot angle 

Length of slot 

Number of slots