I see no advantages other than that, which is a purely selfish, anti-social one.
Our problem is not that the dollar mismeasures average inputs of socially necessary labor-power. In fact it works quite well at doing that, as the system requires. Also, if you want to invest and reinvest locally, you probably can do so more easily do so within the dollar trading network, than in some scheme where you have to convert your local scrip back into dollars to buy supplies coming from elsewhere. Nothing about dollars prevents dedicated local community investing. The capitalist market and its lure of higher profits prevents that.
As to local economies: Great, harmless in itself, except that, as a political program, it's a hugely misleading use of energy. The idea has the same flaw as all the other "turn on, tune in, drop out" proposals out there -- It does not realistically address the main source of our world's problems, which is corporate capitalism and the attendant total lack of democracy in commanding-heights economic decisions.
I'm a GP member, but I agree with the Worker's Vanguard (nothwithstanding their Stalinist verbiage and conclusions) on this aspect -- the Greens way over-emphasize small business and way underemphasize public enterprise.
Unlike the DP, however, there are real ways to combat this problem within the GP, and the middle-class hippie-ism is not the only major viewpoint. There are also lots of us watermelons...