Current status of parsers

I would be interested if anyone would post an opinion on the current
state of the various XML Schema implementations.  (Even privately
would be useful.)

We get email saying "It works on product X but breaks on the TSV"
(we use MSXML 4), and it would be good to have some kind of 
stock answer to tell people "this is a weakness of product X" or
"this is a weakness of MSXML 4".  

I guess this could be done by going through a Schema test suite.

Is any info available?

Cheers
Rick Jelliffe
www.topologi.com