The video Fran posted is by a Bosnian guy called Tiho. He has some of the best videos for arranger players I have seen. He has had all of the major arrangers and describes what he likes and doesn't like about each brand in a very objective manner. Since he uses all brands, he doesn't have a "dog in the hunt." Like our resident expert Don Mason, he says the PA4X is the best all around, but he likes the Genos and SD90 for other reasons. Check him out if you haven't already. A bit of a language barrier, but worth it IMO.

https://www.youtube.com/channel/UC6Kmqz-zLDY3cEkTMxc5TnQ