It makes sense that as cars become more efficient, their efficiency is more sensitive to driving style.
Most AWD's returning over 30 mpg overall have the 2.0L engine. I'm not sure why so many say the extra fuel consumption of the 2.5L vs. the 2.0L is insignificant. About the only people I see complaining about low mpg are 2.5L owners.
I can attest that it is possible to get over 30 MPG with 2.5L AWD somewhat regularly, BUT, the terrain, density of other traffic, hills, number of stop and go events (traffic light stops), and finally my own driving awareness, all factor into this. The last having the gratest impact on mileage, at least in my own experience. While my interest seeing how good it can get has been peaked since getting my CX-5, I don't think driving all the time for peak mileage is a realistic goal in the long run... Just saying while is possible, and I believe easily reproducible in a Test environment, most people just don't drive like that. It takes a great amount of restraint, a quality I see very little of in most drivers-and sometimes myself to achieve. I've employed many tips from this site such as accelerator positioning, coasting, engine braking, and many other hypermiling techniques... The biggest bang I've had came from a combination focused on engine braking, and anticipating the traffic ahead. BTW, I've found the cruise control to be the best I've had yet. I've usually only engaged on previously owned vehicles only when bored, but rarely use, this has changed for me with this vehicle.
That being said, I've been able to consistently get between 28 to 33 MPG during my 2X per day, 17 mile, 45/50/5 country road/highway/city commute. On occasion, this dips down to as low as 24 mph. The best was at 36-the traffic gods were sm8ling on my that day. Every once in awhile, I convince myself it can be better, but then real world conditions brings me back to reality. Time will tell how long this kind of driving will continue to satisfy... Still, it beat the he'll out of the 16-20 MPG I got out of my 6 cylinder Dodge Dakota. Which, much like comparing a 250HP Subie, isn't really quite a fair comparison. I'd take the extra 50 HP if all else were equal...who wouldn't? But given my needs, versus my wants, the CX-5 has only dissatisfied me with only the interior cosmetically. I have yet to be dissatisfied in most every other aspect...still, for everyone else YMMV really applies here.