I've used both in the same project - rented AGA and then bought my own alternative tool. They work essentially the same but AGA tool admittedly works a bit better and has a better fit-and-finish, but that absolutely does not just the cost difference in any way. The alternative tool works just as well. Had I not used AGA tool earlier, I would have thought nothing less of the alternate tool.

As for breaking the tools, you'd have to work very hard and be extremely lucky to break any part of it . Both tools are solid.

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'05 E53 X5 4.4i, '97 E39 528, '07 E92 335i, '16 F86 X6M.