Hey! You should know that Nikon has released a newer version of this product: the Nikon 1 J5.
Introduced alongside the 1 S2, the Nikon 1 J4 is a small step up from the cheaper S2. The biggest difference to note is the touchscreen, which the S2 doesn't offer. The Nikon 1 J4 also adds a bit better battery life and a few more options for the single-point autofocus mode.
Like the 1 S2, the Nikon 1 J4 uses a 1" sensor, which is smaller than most mirrorless models use. However, again, the trade-off for that smaller sensor is the burst speed, which sits at a solid 10 fps, or 30 fps when the autofocus is locked on the first frame. The Fujfilm X-M1 and Sony a5000 will get you better image quality with more resolution, but they also have half the speed, so it's a matter of which one is more important to you.
Disappointingly, the older model, the 1 J3, actually had a better burst mode at 15 fps. I reviewed the 1 J3 last year and really enjoyed the speed and size; the 15 fps down to 10 fps is a noticeable drop. If you can find the older J3, I'd go with that option over the J4, touchscreens aren't all they're cracked up to be. If you can swing the extra cash, Nikon's top-of-the-line mirrorless, the V3, has a burst speed of 20 fps among other perks.