Recently broke my arm.
The store saw ergonomic and decided to try it.
Mouse Prestigio obscure manufacturer, but they are cheap and with all the twists, even weights.

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The mouse lights up like a Christmas tree, the software does not allow to remap buttons, plastic stinks, but the hand went perfectly. Liked it, didn't expect that.
Work proved impossible: can't get. Not like high sensitivity, what would all do without unnecessary movements, have changed less — the situation has not changed. Helped install weights, I was able to hit the buttons. A couple of days hard training and I am now unable to use the mouse, but still not as accurate as the old and with less sensitivity.
What are the advantages of an ergonomic mouse? All trumpeting the fact that the hand is not tired, but I have it and do not get tired. Is it worth it to re-learn what additional benefits? Or cheap not just what I see should not be?