Which XML editor ?

[paul.blast.walker]

I have a fully specified schema against which I can validate my .xml
files. But given the schema is fully specified, the .xml editing
should be a multiple choice activity, using the keyboard occasionally
to enter the field values that would be validated against type. What’s
more, the validation should be an on going process, such that it would
be impossible to create an invalid .xml file.

I have tried a few xml editors, that all seem quite happy for one to
write garbage. On completion if the verify/validate button is
available, it will inform you that the file has validated against the
schema and proffer a few suggestions as to where any bugs are present,
but will not inform as to what should be there instead.

I have also tried InfoPath. InfoPath is almost there, but being form
based, tends to take too much time to construct and what should take
only a few inches of screen space is now screen after screen. What’s
more, the user interface is a pain.

Has anyone found a product that comes anywhere close to my wish list?

The market place is awash with xml editors, there must be one that
does the job.