I never really thought of contrast detection being a defacto standard for getting the most precise focus, but this guy seems to prove the point quite clearly (oh, another pun...sorry!)
http://www.lensrentals.com/blog/2012/07/autofocus-reality-part-1-center-point-single-shot-accuracyand just adding a bit more review info: (from what I can tell, you are still not getting expected results from this
camera/lens combo. I would never say reviews are ever the final word...but your softness situation seems to go beyond review variations or other customer experiences. you can see that some areas both in front (like her sweater zipper) and in back (strands of hair) seem to be sharper than her face/eyes. it might be worth looking into a warranty/quality control issue if all of these cameras/lenses came from one batch at the factory.
http://www.dpreview.com/reviews/nikon-d3200/16Overall Image Quality
At this point in time the Nikon D3200 offers the highest sensor resolution in the entry-level bracket of the DSLR market. That said, you'll have to use high-quality glass to make the most of the sensor's capabilities. The 18-55mm kit lens, while performing perfectly well compared to its entry-level peers, simply cannot transmit the amount of detail the sensor is capable of capturing. Nikon told us some time ago that a large proportion of the buyers of their entry-level models never take the kit lens off their camera. If this is still true, it means that most D3200 users won’t get the most out of their camera. The Nikon AF-S DX Nikkor 17-55mm f/2.8G is Nikon's flagship standard zoom for DX, but it's bulky and heavy, and at more than $1200 not an obvious choice for someone who is in the market for an entry-level DSLR. The Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR is slightly more attainable, but still retails for around $700.
Resolution and detail aside the Nikon D3200 offers good image quality, with reliable focusing and metering. Like we've seen on many previous Nikon models before there is a slight tendency to overexpose in bright contrasty conditions. In those situations it's worth dialing in 0.3 EV or so of negative exposure compensation, but even if you don't, it is usually possible to get at least some blown highlight detail back by applying negative digital exposure compensation in raw conversion (see above).
Image noise is not much of an issue at low ISOs. There are some traces of luminance noise in plain colored areas from ISO 200 upwards, but you'll have to look very closely to spot it. The detail-blurring effects of noise reduction start becoming visible at ISO 800 where some fine low-contrast detail is visibly being blurred. However, you'll have to view the image at 100% to notice. At sensitivities higher than ISO 1600 grainy luminance noise and the loss of low-contrast detail become more intrusive. Chroma noise is well under control up to very high ISOs but gets pretty intrusive at the two highest settings, which should be reserved for smaller output sizes.
Shooting raw files can, with the right conversion parameters, give you a small amount of additional detail. At higher ISOs it gives you the flexibility of applying customized noise reduction and generate better results than the out-of-camera JPEGs, as demonstrated in the sample shot above above.
