Maybe there is more to know than the DME is sharing with you.
Here in the US, I talked to my insurance plan administrator and learned a lot here on abneaboard to determine what my options were before meeting with the DME. It looks like there is somebody called ADP in Canada who makes the rules - see link below for more than I know about it from a casual search I did.
You can quickly scan through previous discussions by googling to see what sort of apneaboard content and forum discussions might be helpful. Here's an example I just did which produced a link I have included for you below:
google search term: site:apneaboard.com Canada
Some links and ideas I hope will be helpful...
* do the above search and you might find other pertinent discussions (btw for single word or complex search terms I often find google searches more helpful than the board search function).
* you might PM some Canadian members who have made posts you want to follow up on, or you could make your own new post with some intriguing title that includes the word Canada or Canadian or some phrase that a Canadian couldn't resist clicking as a hook.
* take time to read this excellent article by Archangle to get yourself up to speed on CPAP machines to consider and ones to avoid. Brand names can be tricky, this is worth knowing when you decide on your permanent machine.
In the meantime, if you can get your way by threatening to return the brick CPAP machine then more power to you.
Failing that, don't be discouraged. Start getting the benefits of your CPAP therapy now and work during the loaner period on nailing down the details and requirements for ADP and your sleep doctor to make the right determination for your permanent machine.
If you happen to come across some info that says you are entitled to a better loaner then take that to your sleep clinic and make demands at that point.
Otherwise just press on to figure out what you need and what your doctor and ADP need from you to make the right smart decisions for your long term therapy.
During the brick loaner period you won't have the detailed data to make your own informed changes, but you will have the benefit of the prescribed pressure from an informed sleep study that got you to here, right? So do what you can and expect to feel better.
Also realize that by the end of the loaner period you will have worked through the personal part of getting used to the equipment and the therapy, so you will have a stable routine that most people don't start with on which you can really depend on and utilize the data once it becomes available.
The log suggested by Sleeprider sounds like an excellent idea, too. This way you can talk to your sleep doc with subjective data about your progress during the loaner period. And if s/he ever says I wish we had more objective data you have a ready answer... we can have that data starting tonight if you will order me a data capable machine now.
good luck and keep your chin up. Believe that things are already getting better for you now that you have begun CPAP therapy.