What are limitations of WiX and WiX Toolset?

I have been unsuccessfully trying to find an article or post listing functional limitations of WiX (Windows Installer XML)/WiX Toolset. After using WiX for a couple of weeks, I can think of at least two limitations in the most recent RTM version (v3.0):

• WiX Toolset cannot make a bootstrapper (setup.exe).
• WiX Toolset cannot retrieve COM registration info from a COM executable.

Can you think of other limitations? Something you ran into while working on a deployment project? I think this info could be handy for people who learn WiX.

It's easiest for me to answer this question in terms of what is WiX missing that InstallShield has ( feature gap ).

• Bootstrapper/Chainer - WiX has a bootstrapper called Burn which is now included in WiX v3.6.
• XML Read - WiX only has CA's for writing not reading ( AppSearch ) XML files
• Text Search / Replace - InstallShield has patterns for reading/writing non INI/XML files
• MSSQL Only - No support for Oracle and MySQL
• Automation Interface - No DOM for programatically updating/generating projects. Have to do it all with raw XML.
• No Native IIS 7 support - Native IIS7 support is present from WiX v3.5
• Mostly Text Only toolset. No GUI Designers for heavy lifting ( see IsWiX ). XML is concise and has it's place but it's like comparing Notepad to Blend.

I've used heat to extract COM fairly successfully so that's no longer a concern to me.