Broke my NX200 6 months ago. Forced upgrade.
Pros:
Nice IQ. Haven't pixel-peeped to compare to NX200 and haven't done much super-demanding high ISO low light.
Improved processing times relative to NX200 (usually shooting raw).
Touch AF useful (mainly use it to move the spot and use spot AF).
Cons:
+AF misfocus frequency seems higher than NX200 (although lock happens quicker). I usually use the 2nd to smallest spot size.
+ Noticeably heavier than NX200 and slightly less pocketable.
+ Built in flash would be more convenient.
+ Processing times still annoying -- but now tolerable -- with a Class-10 Sony card and latest FW.
+ Would be nice to have the 2nd dial. I personally don't like iFn (and use my 30mm that has none a lot). Holding exposure comp changes the role of the dial from A to S when in M mode.
+ Would be nice to have Exposure comp. available as a selectable parameter in M-AutoISO mode. I read this is fixed in NX1 (and hopefully they will update FW to make it available on NX30/300/3000).
Neutral: Haven't played with wifi stuff, 3D, etc. Presumably it works OK. AF tracking is fun but I still haven't played with it enough after 6 months to comment precisely on how frequently it works. Old habits are hard to break.
Bottom line: Safe bet for newbies wanting to build a small lens collection. LR5 bundled is great! (I already owned a copy and haven't bothered selling the new copy, so it was a waste for me). Look at the other systems too: μ4/3, Fuji, Sony, but if you want to buy a couple of prime lenses, samsung is the best deal and is a good all around choice. The lenses for other systems come at a very high premium compared to DSLR equivalents.
Only thing *I* miss from NX system is an intermediate standard zoom like the Fuji 18-55 or Sony/CZ 16-70… with Samsung you have either 16-50 pancake OR 16-50S (I'm sure it's great, but it's HUGE and EXPENSIVE) and nothing in between. I've been considering getting a sony SLT for the reason that the 16-50 is so expensive (you can get an A77 plus sony 16-50 for $1400… an NX30 and 16-50S will cost you $700+$1100=$1800 at current sale prices).
If you're not going to get a fast zoom or some prime lenses, do yourself a favor and just get an RX100/G7X/LX100.
My $0.02.