S-3s are a short form registration and usually clear comments quicker than an S-1. I would use it, but they have to stay current and not miss a report with in the prior 12 months to remain eligible.
But yah, S-3 is a good option for these companies.
If I am missing something, I can ask the better half at night. Spouse was Director of SEC and International Reporting for an NYSE company for a year. Knows the ins and outs of financial filings much better than I do.