I understand that a database is a database (ANSI) but I am curious about some of the things I have heard in the past. I know that poor datamodeling and scripting is due to the designers error. Just being Inquisitive I suppose
Oracle does have a steeper learning curve than Sqlserver or Sybase but then I would argue Oracle is a better product IMHO. The fundamental difference is that Oracle has been designed for worst case scenarios and they have provided the tools however complicated for you to diagnose and solve those problems. Sqlserver on the other hand has been designed for the best case scenario and they hope you dont come across lots of people all after the same bits of data. So if you mainly have a few connections, mainly doing reads and not looking/modifying the same bits of data then great, Sqlserver will kill Oracle. Get thousands of connections doing lots of reads and writes against the same bits of data then Oracle will kill Sqlserver, just ask any sqlserver dba about the joys of escalating locks .
As for the steeper learning curve get a good tool like Quest TOAD. Also dont forget Oracle is pretty damn reliable which is useful for 24x7 systems .