Native XML and XML Enabled database

Hi All

I want to know decide between XML Native (e.g. eXist, X-Hive) and XML
enabled (e.g. DB2, Microsoft SQL server 2000)

Following is the list of the features by which I want to compare them.

1) ordered access
2) User defined Function application 
3) Sorting
4) result construction in XML format
5) Text Search
6) Joins on values
7) Datatype casting
8) Aggregation

I want to know which of above features are supported by current Native
XML database and by XML Enabled database?

Thanks and Regards,
Priti.