S-Corp customers also don't have to worry about 1099s. They also tend to offer substantial tax savings vs a C Corp. They are less attractive to VC investors, but should work fine if the author plans on scaling by introducing partners instead of passive investors.
Definitely go the c-corp route. You'll have an easier time closing deals since your customers don't have to issue 1099s and can just pay your invoices. And if you ever do find someone willing to invest, the stock issuance is so much easier than dealing with LLC operating agreements.