Though I don't own them, I do own a lot of Mac wrenches, new and old, xl and stubby, and have never had a problem. There are a lot of Mac haters round' here these days, but I wouldn't be afraid of buying them. It is odd they are the old V jaw style.
I have the set. I use two wrenches the most (13x15 & 16 x18) for holding brake caliper pins while removing the caliper bolts. They're thin and cannot handle a lot of torque. If you're not careful, you could dent up the open end trying to break a fastener loose with them. I only use them when my combo open end is too thick. Nice wrenches