The BK9 does have a rhythm composer, and you can save your "user" style..
The EA7 's sampler is easy to use and is under rated by folks that never used it.. The key being to save your samples as user tones..

Advantages of the BK9:
76 keys, 16 track sequencer, 22 SN tones, 6 fills..

Advantages of the EA7:

Speakers, improved panel controls, sampling, pads, 7 control buttons..