Rolex is -2/+2 spd.
GS hi-beat is +8/-1 spd. The three hi-beat I have owned (bought the new) have all been +7/+8 spd. So for me, the GS hi-beat movement is a gimmic. It’s not accurate enough to valid the disadvantages of hi-beat.
Regular GS mechanicals are rated +10/-1 on the wrist.
I base my GS buys on the case, not the movement type and today I own a quartz GS and a hi-beat GMT. If I was to base my GS decisions by movement it would be quartz>spring drive>low beat>hi-beat.