Wox looks like it has a lot of potential, but it was far more annoying than helpful. It's actively being worked on so I have high hopes for it eventually.
However I just found a new program in a very round about way (I started using Text Editor Anywhere) and ended up finding Listary.
My initial reaction after a brief honeymoon period is 'Holy shit, where have you been all my life.'
It's like a cross between Launchy/Wox and Everything - I think it uses the same NTFS index as Everything because it had instant access to all my files and searching was instantaneous.
No plugins and there is a $20 pro version but so far I haven't needed any plugins and the freeware version certainly isn't crippled.