While it only has four types of forms (NEC, MISC, INT and DIV), I can say that the "Intuit Solution" [Quick Employer Forms] worked reasonably well last year for a reasonable cost.  The GUI could use some improvement and if you need to issue an OID you're on your own but....if not trying to issue thousands of forms, it wasn't bad.  I'm thinking better than IRIS but I haven't used IRIS so I don't know.  Simply did not want to rely on the government system to get the job done.