The reason I like time limited meters is often that they get me closer to where I want to go downtown then a garage would be. I think that is why they are trying to put these in. There is really no benefit to putting meters in an existing parking garage in my opinion.
And what happens when you hit peak happy hour and the meters are taken? Like i said, I get why they can be good and why they are needed. But the current proposal is going to restrict usage at peak rush hours, so there goes 4 hours of parking plus the potential of a hefty fine and no car if you are running late. If you're meeting people or going out at night, you may get lucky but chances are you aren't getting that coveted space. I don't think I am suggesting that meters in garages replace totally the meters on High, just that it can go a lot further to challenging perceptions and make downtown seem easier to navigate.
If we're going off personal anecdotes, I love meters during off peak day time hours but they are useless otherwise. For a visitor that's going to be a huge punch in the gut and make it far more likely to flee to Easton where parking is "free".