My experience with sealed cartridge hub bearings is that they can be almost impossible to remove with the correct tool.
When confronted with that situation, simply resign yourself to replacing them in pairs, and warm them up real good with a torch: Then they'll just pop right out with a screw driver (so easily, that you may have to duck!)
I like them because their durability is good, they're cheap and easy to replace (as above), and they make for one smooth running hub.
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- Auchen