I am so strongly right-handed that I doubted that it would ever work, but about a year ago I saw several posts describing how great it was for right-handed people to free up their dominant hand for writing, phoning, etc, not to mention the fact that the left hand does a lot less reaching.
As a regular numpad-user, I was not prepared to give it up, no matter what, I even bought a laptop with a numpad.
I am in my 50s, so new tricks are hard for old dogs, but it was terrible for a week and awkward for a month, and after that, smooth sailing. Now it seems totally natural. Surely a younger whipper-snapper could make the change a lot easier than I did.
PS - naturally you should get a symmetrical or ambidextrous mouse. if you like those extra buttons for the thumb and whatnot, it may be harder.