The honest answer is that what is considered best is what works for you. We're all different, and we don't know enough about the subtilties of COPD to understand why some meds work better for some people than others, so right now, no one can really answer the question. There's a lot of research going on about why people who generally present the same respond differently to identical meds, but we don't have definitive answers yet. So my best advice is to try both and see which works best for you.