I have flown others Futaba but haven't been a regular Futaba flyer since my 9c.
But I fly jets on the Core and love it. The feel is outstanding, the machined field effect gimbals are like butter, the RF link is rock solid and the while the programming is less intuitive than Spektrum, its much easier to wrap my head around the principles than Futaba and once I set up a model or 2 I can fly right through it now.
The telemetry is amazing, the isat gyro is a little beast. Receiver firmware is updated from the transmitter via the interface.
I haven't found anything I don't like about it yet