Questions on the APAP machines.

I am about to purchase my very first CPAP/APAP machine and have some questions.
After Searching around, it seems like APAP is more preferable than CPAP because APAP can also be set to CPAP mode. However, I am
wondering what APAP machine would be the best out there.

(1) Any comparison/suggestion between the RESMED SA8 and Respironics HM series Ramstar Auto Cflex? Is one much more advanced, quieter, or better than the other? That seems to be a hard question but I appreciate if you can share your own opinion.
(2) Because the original END is impossible to reach and the original prescription is very general, the DAMS told me I will get the basic one. So If I am going to see my family doctor for a more specific prescription, say an APAP like the "Remaster Miseries Auto Cflex Heated Humidifier, will my Bluegrass BlueShield of Illinois (I live in California) PO allows me to the Encore Pro SW.... I like the idea to be able to further understand the sleep myself as I am not sure if the sleep study I had about 1.5 year ago was that accurate (one nite split-session study may not be as accurate as an evaluation over a long period of time...) Will the sw feature an overkill for a new user?

(3) I have read the following differences between CFLEX and Resmed's
EPR. However, as I am just starting to understand my sleep apnea problem, there are a lot of terms that I am not sure what they mason. Could someone elaborate further particular on the fact that the EPR works more like a BiPAP level (but within on -1,2,3) is this something GOOD or not SO GOOD compare to the CFLEX 1 second drop. The following is a recap of the whole article:



Respironics CA-Flex fs. Resmed EPR: There Is A Difference

Many similarities exist between Respironics C-Flex and Resmed EPR
but they are NOT the same thing! Both are easy breathing, expiratory pressure reduction systems. Both decrease the pressure to the patient at the beginning of each exhalation and both have three comfort settings.
However, major differences exist in the availability and effectiveness of
these features.

Here are a list of the major differences:

* Auto Mode Pressure Adjustments. C-Flex works when the machine
is in
the "Automatic Pressure Adjust", or "Auto" mode. EPR only works in
"Constant Pressure", or "CPAP" mode. EPR will not work when an S8 Vantage machine is in the "Auto" mode.

* Length Of Pressure Drop. C-Flex decreases pressure at the
Beginning of each breath. The decrease lasts for less than a second and then returns to the base pressure. EPR decreases the pressure at the beginning of each breath also but keeps the pressure low throughout the exhalation.

* Relative vs. Exact Pressure Drop. C-Flex settings reduce the
Pressure relative to the patient’s exhalation strength and the machine
Pressure setting. EPR reduces the pressure by one, two or three centimeters of water pressure.

* Sleep Disordered Breathing Event Handling. EPR has an Event
Detection Circuit. When a sleep disordered breathing event is expected or has occurred, EPR stops until the event concludes and normal breathing resumes. C-Flex is of such short duration it is thought that is has no negative effect on sleep disordered breathing events and does not need to stop.

* Ramp Mode Pressure Relief. EPR can be limited to work in the ramp
mode only. C-Flex can not be limited in this way. So, if EPR reduces the expiratory pressure by a controlled 1, 2, or
3 centimeters, what is the difference between EPR and BiPAP (tm) or
Bilevel?

Bilevel machines are categorized as "ventilatory devices". They use
Rapid pressure changes to expand and contract lung volume. EPR uses slower pressure changes, so there is little ventilatory effect. However, EPR does feel very much like a Bilevel to the patient. (IS THIS VENTILATOR EFFECT DESIREABLE or NOT??? )

If you plan to get an autopap and want to use some kind of exhalation relief from pressure while using the machine in autopap mode, this is important to know:

There's a company that touts "EPR" as their exhalation feature, but the "EPR" cannot be used when their autopap is operating in autopap mode. It can be used only when their autopap is switched to operate in straight cpap mode.

Respironics's "C-Flex" can be used when a Respironics autopap is operating in autopap mode.

As far as I know, if you want autopap operation PLUS exhalation relief at the same time, the only machines that can do both at the same time are made by Respironics. I'm not counting machines made for very specialized purposes like the ASV.

The Respironics machines (auto + exhalation relief at same time) I'd be considering are:

REMstar Auto with C-Flex
REMstar Auto "M" series (has C-Flex)
BiPAP Auto with Bi-Flex