Is the climateline hose as flimsy as the slimline hose?

Is this hose flimsy? Probably, but repace it often enough and ResMed will run out of stock and newer, sturdier ones will certainly follow and then you can replace the flimsy with one of those. If you just want to stop rainout then buy a hose cover or an Aussie hose and these will work more than adeqately and you don't need the S9 anymore. However, if you want to deliver a prescribed amount of moisture to the nares of your nose or (gasp!) lips of your mouth, buy the climateline. The climateline is part of a designed "system" that guarantees an amount of moisture to the mask that has been shown to be effective to subjects who have used the therapy in studies where temperature and humidity were controlled and varied and subject data (objective and subjective) were collected. Realize that we're not talking about relative humidity which is given as a percentage but rather absolute humidity, which reflects the amount of moisture actually in the air and is often given as mg/L (milligrams of water for each liter of air). The numbers also correlate well with published results for required humidity for nasal tissue performance and cpap compliance. Absolute humidity and not relative humidity is controlled all the way to the mask when used as a system. You even get to select a mask air temperature that is comfortable. Substitute another hose and all bets are off. Protecting the hose with covers and heating elements will prevent rainout but who knows how much added moisture you're getting (or not)? If it works for you then you're a winner and we're all happy........I think. You have spent less money with more robustness and prevented rainout. If it doesn't work, then you have to make a change to your setup and what will that change be? I didn't buy this unit because I thought it was pretty or made out of ship grade material. I bought it only because I could dial in the temperature at the mask and it claimed to give me more moisture. It was that simple. I didn't have to feel like I was being smothered when dialing up the humidifier. More moisture at a temperature I could select? Bring it on! I wanted to be transported to better times and places and feel like I was still on a mountaintop in Hawaii with my arms spread and my eyelids closed and breathing in the joy of life when wearing this mask. This was the vision I had in my lab environment when first fitted with a mask and the environment I have tried to recreate every day since.