I have a vibra impact gun and I have mixed reviews on uts use. I have removed a few tight glow plugs with it but also broke a couple with it. With the tight ones that were removed I have know way of being certain they couldn't of been undone with a ratchet/socket and care but its just easier to use the gun.

I did persist with 1 plug that was very tight, plenty of plus gas and gently working up the torque range did seem in all fairness to persuade the plug to give in so I reckon its like everything it has some use but if its going to break it will no matter what tool you try.

I bought the bgs version but it does seem good quality.