andre_
if you can not give a try to both, you can be brave and asimilate as much info as you can, listen to all demos available, ask questions, surf the internet, watch pictures...
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eventualy, you'll know the keyboards good enought to have a general idea. after that, just go for it!
oh, should i say also that this worked for ME. for many others, it would be just crazy ordering without trying.
diki_
the manuals are improuvable, but at least roland's and korg's are a little bit more professionaly put in the page. psr3000's manual i really did not find it reliable.
i think korg pa's manual was the best written, explaining what is in every page from menu and how to get some things done...