The one begets the other: if the average size of XPT executables is 7.19KB and if the XPT is already famous for leaving absolutely no footprint on the host system then obviously the XPT is your ideal USB thumb toolset. No contest. You can easily fit all 150+ XPT applications on the most meagre of USB thumb devices. And yes XPT applications do this weird thing: they just run - they don't have to be installed (or uninstalled either - isn't that like weird?)
Admins: put the XPT on your thumb and you'll want for nothing else.