Alain,
First of all, I don't know who it said, but I know this is said at least once by someone at this forum; 'The amount of posts doesn't say that much about the popularity of a keyboard.' So there's nothing to worry about. Maybe no one asks because the VA series of Roland do come with a very good detailed manual. Additional tricks (as you must have seen) are posted on this forum. You can also do a search on this forum.
Sample sounds are available on
http://216.133.225.74/images/varranger_flash/DEMO.HTM . I will post some MP3's soon also recorded from a VA-7. The samples do not differ at all. The VA-5 and VA-7 both contain 48 MB PCM-Samples (3694 sounds which include the 116 drum sets).
Again, $835 is a very good deal for the VA-5.
Sander