We use the respironics i neb. We use xopenex, pulmozyme, tobi, hyper saline. I have never heard any different. One of the posts before this says tobi was only tested with the Pari, but our doctor hasn't said that our neb is bad. She just prescribed this one. We are part of the Stanford CF Clinic so I was going to ask next time we go but like I said this neb is brand new.