Some comments from my first change on our 2012 this past weekend. Easy peasy; no real need to remove the splash guard, though either a short oil filter wrench or - preferably - oil filter socket is required.
I took a sample; curious to see how the oil looks since we've had it since just 6km on the odo, and I'm doing this OCI at ~4100km (2500 miles).
Mazda says it's 5.0L capacity... I got just over 4.5L out, and that was with the dipstick showing about 1/3 above the min fill mark. Figuring it's about 0.5L between min and max fill (and not knowing exactly how much the factory put it), that's pretty good.
Filled with M1 0W20 (green cap); locally, it goes on sale regularly at Canadian Tire, $9/L instead of $12/L (or $11/L at Walmart).
Used a Purolator PureOne PL10241 filter... knowing what I know now, I would have gotten the taller PL20195, as the additional ~1.4" height wouldn't be an issue, and increases the filter media surface area accordingly. Also, on the PureOne filters, the textured finish is great. You could get away with hand-tight, even, because you can get such a good grip (although I did an additional 1/8" turn with the wrench for certainty).
There isn't much doubt that an extractor is going to get more oil out than the drain plug.
Also, FYI, with the car still on ramps, I stuck the Pela (fluid extractor) in to see if I could get anything - nothing more, really.