they worked ok at first but under any moderate torque they will twist or break but i used them daily in a auto shop i replaced them with snap on and never looked back but I hear gearwrench is also good i have some of there sockets and ratchet all of which are awesome
Both shops i worked at had the rotary a symetrics and they were great the biggest thing we had on them was ford e350 wheelchair taxi vans probably around 10k lbs and it was no issue.