I would go with the ENT recommendation first, because what works in lungs and sinuses may not be the same - and with the caution that a typical course of antibiotics is often too short for a sinus infection and may need to be repeated. If the Cipro doesn't work, then maybe ask them to do a susceptibility test on the culture. Many kinds of pseudo can be hard to treat due to antibiotic resistance.

Also, this may sound silly, but there are sometimes geographic differences in what works on a specific infection. I acquired a staph infection in wound while in Texas, the doc treated it with doxycycline, which usually works for me, but he had to switch to another antibiotic to finally cure it. So if your local ENT says Ciro, it may be the drug he has found most effective.