Sony makes cameras that are easy to love. Not all of them are perfect, but when it comes to design, Sony usually has an edge. That was lost with many of the Alphas, with the exception of the high-end of their body and lens lineup. We definitely see more of Sony's acute design skill built into the NEX-3 and NEX-5. Though physically they are very different, functionally they are nearly identical, so I'll talk mostly about my experiences that are familiar with both.
Dust. The Sony NEX cameras have a dust abatement and removal system, where they've included a charge-protection coating on the low-pass filter, and they also vibrate the low pass filter to shake dust free.
While they don't power-up quickly, the Sony NEX cameras do focus and fire quickly, especially in good light. Focus can take a little longer in low light, as with most contrast-detect cameras. Powering the camera on, though, is a little like watching yourself wake-up after a very deep sleep. You flip the switch, and nothing happens. Then after half a second, the icons appear onscreen. Then after another half-second, the view begins to fade in, from blackness to a dim vision, to full brightness. I confess I've never seen a camera do this. It takes long enough that I've more than once had to check to make sure the lens cap wasn't on.
Note the position of the two camera strap lugs. The Sony NEX cameras are designed to hang with the lens pointing down, just like their spiritual predecessors (the F505-F717 mentioned earlier). This has several advantages, one being that the screen is less likely to be scratched by shirt buttons, and the small camera body won't pitch forward at different angles depending on what lens you have mounted. Sony knows that the lenses will usually tip the camera forward, especially on a camera whose body is so light, so why not just hang the lens downward in the first place? What I discovered when I attached the strap was that several of the camera's design elements that seem awkward at first suddenly make perfect sense.