I heard that question a few times at MMS 2008. Why? Because we were handing out trial CDs of ScriptLogic's MSI Studio at the booth.
No, we don't sell it, nor are we affiliated with ScriptLogic in any way. We just promote it as an alternative to InstallShield/AdminStudio and Wise. Why? Because there's a huge hole in the MSI creation/editing market created by the top performers in this industry area.
No one seems to like the familiar options that are out there. I asked several people at MMS 2008 and I couldn't find anyone that could say something nice about the other products. There was always at least one "gotcha" with the product they were using.
Why am I reminded of this suddenly? I was just reading some comments in the forums...
http://www.myitforum.com/forums/m.asp?m=178297