As has been stated before, if thinness is what you want, go with the 7000.
However, unless you are planning on wall mounting the TV, you will soon forget whether your TV is 1 inch thick or 3 inches thick.
At the same time, remember there may be a cost for that super thinness in terms of sound quality should you plan to rely only on the internal speakers. (Most reports say the B750 has better sound, possibly because of the thicker cabinet and different speaker placement).
While I was intriqued by the edge lit LED models and their thinness, what ultimately made me order the b750 and not get an LED model, was the off angle viewing washout of all LEDs, and the many reports of flashlighting, and occasional clouding complaints, not to mention the dimming problemspeople complain about with the LEDs. What has been special about b750, at least so far, has been the lack of ANY consistent complaint with this model.
I agree with others who state that the LED technology has not been perfected, especially with the edge mounted models. Frankly, I will be surprised if the off angle viewing issue can ever be eliminated. If you think about an LED and how focused and projected a LED point source of light is, it is hard to imagine how off axis brightness differences can be significantly reduced, much less eliminated, unless the number of LEDs is drastically increased. I guess that could be done, but we are unlikely to see that on any set that is remotely affordable to most of us.