Also the nice thing about banks is that they don't like to make mistakes, and are better about reversing errors than any other industry.
The only downside is that it takes about 3 days for money to move - apparently that's the speed that the checking network moves, but since paper checks have legal guarantees, the banks are willing to take the risk during that time - that's how you can cash a check and have it "bounce" after you've already withdrawn the procedes from it. Without the paper check, you just have to wait for the EFT system to do what it does (and the technology is old and weird - I think it was designed in the mainframe days - so it's all based on batches of processing, instead of on-line immediate stuff)