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...
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...