I've been using StylePix version 1.8.3 for quite some time, in fact since before I discovered the Portable Freeware Collection. I initially installed StylePix the conventional way, then copied the StylePix application folder to another location on my HD and uninstalled the app. It's now running from a subfolder of My Documents (in Win7), and leaves the same traces behind as its so-called "portable" version - no more, no less - so if it's going to be used on my HD, there's little point in downloading the portable version. I'm not desperate enough to enlist the aid of a secondary utility to "virtualize" the settings.
Anyway, I tried the latest version (1.9.0), but various changes to the user interface annoyed me, as I had everything set up the way I liked, so I reverted to 1.8.3. StylePix is great for pixel editing, and I unassociated MS Paint (which I hate) in favor of StylePix. It handles transparency very well, so I often create icons with it. Unfortunately it can't be trusted with the photos I've taken, as it will delete their EXIF info when saving, so I use XnView for enhancing my photos.