For a couple years after my diagnosis, I use the Pari trek S but then switched over to an Ombra system by Monaghan. Both companies make excellent machines. I like the Ombra because it works well with two other products the company manufactures - the Aerobika and the Aeroeclipse nebulizing cup. Also, National Jewish Health recommends the Ombra system as they say it is most similar to what they have in the hospital.