I've been using the Rebismart machine since October 09. You can keep the rebif out of the fridge but only for 2 weeks (the 44mg cartridge only lasts a week anyway so no danger there). It's recommended that you keep your cartridges in the fridge until you need to use it. What I do is I inject on Mon, Wed, Fri and when the cartridge is empty on Fri, I just insert the new cartridge ready for Monday. I find it much easier this way other wise I would forget to take the injection out of the fridge in plenty time or doing the injection altogether. If you are recommended to try the machine, I would say to try it. It takes out all the guess work and reminding for me.