I agree. It all depends on the nature of your sleep issues. If you are a classic OSA sufferer (lots of obstructives, not so many other types of events, no Cheyne-Stokes, etc.), a PAP that will do APAP (will titrate pressure automatically) makes sense, but only if you can parse the data and use that to find the proper range. Otherwise, narrowing the range is not much more than a wild-ass guess. And leaving the range wide open is probably less effective in many cases than picking a reasonable CPAP pressure that stays the same. So APAP can improve your therapy above what CPAP can do, but it will only improve things if it is applied properly; otherwise it might be somewhat counterproductive.
Most of the time they are prescribed to start out at 5-20 or so, and the data then reveals that the range can be narrowed and to what. Essentially (for classic OSA) you want the minimum high enough to prevent obstructive events, but the maximum low enough to not create central events. You can sort of do that on your own if you have Sleepyhead SW and a XPAP that can collect data on an SD card, but it helps to have the guidance of a sleep doc involved in this (and they are more focused on full sleep studies and whatever info they can glean from that).
There is also no true connection between how you feel and how well the therapy is working, so don't rely on that to tell you, and don't base your usage or pressure changes strictly on that. You need numbers that can be read and understood to evaluate efficacy and fine-tune settings optimally. How you feel might be a factor, or it may not and may point you in the wrong direction altogether.
Sleeprider is representative of what a lot of us do (because the sleep docs don't get as involved as they probably should, sadly). These forums and software to interpret the data are both great tools to improve your therapy. Understand what is going on, apply that to fine tuning the APAP, and you are likely to have good results.
I used a ResMed Escape S8 for over 6 years and changed it out with a ResMed Air Auto Sense 10 a couple of months back, mainly because the fan bearing of the S8 wore out and it started making a lot of noise. My S8 did not have any auto adjust mode and it was set by my CPAP provider at 11.0 cm/H2O. I was not getting very restful sleep and the new Air Sense 10 is bracketed to 11.0-15.0, which improved my sleep drastically. It reports that I am mostly at 14.0 so that shows me that I have changed my needs for a different pressure over the years. At first I was skeptical of the auto adjusting feature but I am now a big fan.