Having had the opportunity to have worked with all 3 of the aforementioned machines, I'd say beyond any doubt that Biorad is light years ahead of Ortho. You get definitive results with Biorad, not the untold and innumerable false positives using Ortho reagents and products. I don't remember having any major downtime issues with Biorad apart from the expected wear and tear of a robust machine running 24/7 - 365.
The turnaround time using Biorad was much better.
Maintenance schedule is a breeze.