Give Boxer text editor a try, of the text editors I use or have used it seems to be the most nimble with large files.

Edit:
You might also try Editpad Lite -- it's big brother, Editpad Pro, has always been more efficient than Notepad++ or e, Lite might be a viable solution and it's free.

Anybody who uses dropbox can earn an extra free gigabyte of space by completing this scavenger hunt:

https://www.dropbox.com/dropquest2011/

The exclusions functionality in the settings appears to be filename only, is this the case? I'd stopped using CHS because it logged passwords copied from my password manager. I see that in the options, it tells me all sorts of info about the last active window -- is it possible to use this information (namely %windowtitle% in this case) for exclusion?