I found some very nice video’s explaing these 2 imcredible instruments
Not just the differences, but also how they work and what they have to offer.

http://keyszone.boards.net/thread/538/nord-stage-elektro-comparisson-video

Now this seems not related to arrangers
Until you realise that these might be the perfect controllers for the ketron sd40
Or any other arranger module for that..

A combination like this might give you the best of both worlds...