For traveling or outdoor use it is perfect:
I can squeeze it together with my old beaten up guitar in the same guitar bag, throw in a Bluetooth speaker for the Korg to use it together with phone's midi app and go jam in the wild.
For home use, personally i wouldn't recommend it:
The small micro keys just cannot be compared with standard key size, it is just not as satisfying to play (i have pretty large hands and everything feels cramped together). The quality and feel of the keys however are decent, definitely better than most budget synths. The compact size is sweet for travelling or outdoors, but for home-stationary use i would go with something else.
Build quality: really really good for the price!
Wireless/Bluetooth functionality is Really really bad:
1) Till today i haven't found a way to hook it up with my windows PC.
2) My old android phone needed another app for it to work via Bluetooth (BLE midi or something was the name). It won't work with my new android phone - i have tried everything.
3) When the wireless BT douse work it would sometimes have a massive latency making it unplayable.
I have the korg for 1,5years - I've used the wireless Bluetooth successfully maybe on 2 occasions for 30mins each.
