Because. They’re too different. User Interface is pretty different. Menus. White Balance and exposure preview behave differently. And external controls are in places different enough that switching between both will let you turning the wrong knobs and pushing the wrong buttons. It’s endless frustration waiting for you trying to shoot those cameras side by side. Not to mention that the A6000 feels totally competent and very nicely built in your hand… Until you pick the NEX7 right after. You’ll be longing for the N7’s densier weight, softer/thicker rubber grip, slanted top plate, larger EVF (sexier looks ?)
So don’t make yourself miserable. Decide which one you want to chose. Once the N7 is out of the way, you’ll be able to enjoy the brighter EVF of the A6K, its additional controls, MUCH friendlier menus, better customization, and of course, insanely faster AF.
But let me try to sum up differences for you :
TriNavi. On the NEX7, you have three separate controls to access “live” (without pushing any button first) all three summits of the exposure triangle ; aperture, shutter speed, ISO. In Manual mode the left top wheel controls shutter speed, and the right one aperture. In semi automated modes (A and S), the left top wheel controls your setting of choice (either aperture in A, or shutter in S) and the right top wheels accesses exposure compensation, meaning you’re always just a dial spin away from your desired exposure. And in all modes the rear thumbwheel offers direct access to ISO (unless you want to lock it to prevent it from changing them too easily, as it is prone to).
On the A6K, Sony has done the right thing. Well, almost. They put the damn, stupid Mode dial (I hate them) on the left, and the setting, customizable dial, on the right. The opposite would have been ten times better, because the Mode dial falls totally naturally under your thumb, and that’s the one you’re gonna blindly try to turn when shooting with the camera to your eye. Anyway, aside from this fundamental blunder, Sony did do it right, in allowing the top setting dial and rear thumb wheel to be swapped at will in both Manual and semi automated modes. In Manual you can have either the top dial changing aperture or speed, the other setting being assigned to the rear wheel (I’ve chosen speed, which is what I alter constantly to reach optimum exposure). In A and S, you can decide whether the top dial changes aperture/speed, or exposure compensation, the remaining setting being assigned to the rear wheel (you guessed, I chose to have exposure compensation on the top dial, meaning that whatever mode I’m in, exposure is always tweaked via that same dial, albeit its rotation is reversed in this case, but let’s not create more confusion). ISO ? Assign them to any of the Custom buttons available, or leave them by default to be called by the right spot of the rear thumb wheel. The ONLY downside, is that ISO doesn’t have “live” or “hot” access anymore, you MUST press a button (of your choice) before altering their value.
Other external controls : The N7 had the small, unmarked button next to the shutter release that always made me feel like James Bond, because it could call up to five pages of personally chose goodies known to you alone (I loved the “unmarked controls” scheme of the N7, it was such a groundbreaking approach to UI at the time). I had only enabled 3 of those pages that I could cycle through by another press of the small button. The there was the lower left, equally unmarked soft key, the large center button, and the right spot on the rear wheel, that could be customized at will. That was very good for the time, except the choice of options assignable to each control was way too restrictive to be optimally useful.
The A6K takes it to a whole new level. All but one spots on the rear thumb wheel are customizable, as are the AEL, C1, C2 and large center button, plus the Fn button calls a superb, up to 12 item, menu, and the available options cover *almost* everything you’d want to assign them (except for “Format” and “Live View Settings On/Off). Truly, if I decide to revert to the N7, and let go of the A6K, tomorrow, weirdly it won’t be the super duper fast AF I’ll miss, but that wealth of buttons and personal options. It makes operation very fluid and enjoyable.
White Balance : the cameras approach this totally differently, and since exposure preview is also not the same, there is a real gap in use between them here. The A6K, like the A7 before it, has a rather strong Green/Amber bias, while the NEX7 has a Blue bias, so their approach to WB is really different. I also always found exposure preview to be very, very reliable and accurate on the NEX bodies, but both the A7 and A6K drive me nuts by giving a final image that is always one good notch darker than it appeared on the LCD/in the EVF (even when you tweak them to try to compensate). For info I always shot my NEX cameras with DRO set to 1, but have now switched it to Auto on both the N7 and A6K. Output wise, I feel the NEX7 offers much brighter midtones, while the A6K needs to be overall more exposed not to look dark/dim. Very interestingly, both the A6K and A7 *lose* 1/3 light vs. the NEX7 if you try to match exposure in Manual mode, at any ISO and with any lens that I have tried, giving the NEX7 an actual ISO advantage (or let’s say compensating its disadvantage).