Constraint Vs Compatibility Rule Performance

Dear Experts,

I need your inputs related to performance.

1) Root Product A

     - Chidl Product A1

     - Child Product A2

suppose both are in different relationship.

A1 is not compatible with A2.           

I can achieve in both ways.

1) A1 Exclude A2           ---> Using Constraint (A2 will be in Red if i select A1)

2)A1 Excludes A2        -- > Compatibility Rule with prepick. (A2 will be in red if i select A1)

Which one is good for econfigurator performance wise  ? Constraint or Compatibility rule with prepick enable?

Regards,

Raghavendra