I use the HME's with my Z1 4 out of 7 nights most weeks because I'm on the road. They last anywhere from 7 to 14 days. I am the type that if I don't have humidification I wake up in the middle of the night dry and very uncomfortable. At home with my PRS1 w/heated hose I use the highest setting for humidification.
The HME's keep my from drying out but they certainly don't have the same comfort level as heated hose hose humidification. They get better once they heat up with your breath.
I tried traveling my my F&P 150 but that was so bulky that I might as well had brought my PRS1 so I stopped.
I'm heading out tomorrow and I'm bringing my Z1 Auto and HME's. I usually keep 2 new ones in my bag or one new one and one used one. When I'm not actually sleeping and using them I store them in a zip lock bag during the day.
All I can say is that they work for me.
I've used the HME option for the Transcend. It's not nearly as good as proper heated humidification.
One thing to consider. Check into the filter medium for the HME the Z-1 is using. Some HME medium can be "pre-loaded" with a little sterile saline. I use a little squirt from my NeilMed nasal irrigation spray. The HME for the Transcend can be "pre-loaded" I don't know about the Z-1.
It's amazing what you can learn going to a sleep medicine trade show.....learned this at Focus in Orlando last summer.
(Just a truck driver with sleep apnea )