I like that it's very easy-to use compared other software out there in this category (i'm sure others have similar features).
It does what you want without much hassle or learning curve needed by your end user - great! The only thing i dislike about xmlspys ease of usage was when we used their services as our internal developer toolkit at work; some functions are hard coded into certain modules which can be difficult if not impossible using another IDE/editor outside xmllint itself such us Notepad++ etc.. Overall good product but would recommend trying multiple IDEs before making final purchase decision since each one has different strengths / weaknesses from my experience so far.- Easy accessability across platforms including windows desktop & server version support via command line terminal prompt interface available through cmd window also supports linux platform too.