How does this make voting faster,easier and better?
All right, let's consider the recent Republican primary. People had a choice of Michelle Bachmann, Mitt Romney, Herman Cain, Rick Santorum, Newt Gingrich and Jon Huntsman (among others).
Let's say you lean right, and think Romney is too far to the left. You like Herman Cain and Michelle Bachman a lot, with Michelle your slight favorite of the two; you could settle for Rick Santorum; you think Newt isn't much better than Mitt, but at least he isn't the father of RomneyCare; and you think Huntsman is as bad or worse than Romney.
As things stand, you're forced to pick which one of the not-Romneys you think has the best chance of beating him. All the other folks who don't want Romney are also faced with that choice. Result: when the smoke clears, you likely wind up with Romney.
With IRV, you mark your ballot according to your preferences:
[1] Michelle Bachmann
[2] Herman Cain
[4] Newt Gingrich
[ ] Jon Huntsman
[ ] Mitt Romney
[3] Rick Santorum
1, 2, 3, 4. Easy! You don't need to agonize over which one's got the best chance to beat Romney; you just mark down which ones you truly want, in the order you truly want them.
Let's suppose there were a lot of other folks who loved Michelle as a candidate but under the current system were afraid to vote for her because they 'knew' she couldn't get the nomination. Under IRV, there's no such fear and they're free to vote their true preference. If Michelle is who people actually want they've got a good chance of getting her.
But let's suppose she's not all that popular, and that you were in a small minority. Let's suppose most of the right-leaning folks liked Rick Santorum best. Under the current system, you're out of luck if you voted your true preference; by voting for Michelle rather than Rick, you kept Rick from getting the votes he needed and Romney emerged triumphant. In November you'll have a choice between a socialist and a socialist.
But with IRV your vote isn't wasted. If most people prefer Rick to Mitt then Rick gets the votes and is declared the winner.
Same things applies from the left. If, say, in 2008 you didn't like either Clinton or Obama, and there was a lesser-known candidate who represented your views better than either Clinton or Obama, you could have freely voted for that person without worrying that by doing so you might be helping Clinton win (if you preferred Obama to Clinton) or that you might be helping Obama win (if you preferred Clinton to Obama). So again, no agonizing, no long debates with your conscience, and no feeling dirty when you emerged from the voting booth.
Under the current system, candidates tend to win because they're considered electable. Under IRV candidates tend to win because people are excited by them and want them in office.