Yeah, those are neat tools. Never owned one; I've wished I did once or twice.
I owned a BMW motorcycle, on which the swing arm for the rear axle ran in tapered roller bearings in blind holes. I had to replace them, and was shown a neat trick: heat up the outer race with a torch to red hot, then let it cool. As it contracts, it gets loose. Very effective, but a little scary. This tool would have been better.