Your answer is in this thread:
http://forums.codeblocks.org/index.php?topic=994.0Resuming: There is almost no diference between both, and some quick tests revealed that the Inno Setup version appears to be smaller than the NSIS version.
Anyways, the Inno Setup files are already there and working, so there is no advantage in changing to NSIS, if it provides the same size (or worse), and same features for what we need.
As a side note, I personately hate win32 installers.
I think the way to go on windows would be imposing a standard like MacOS haves: .dmg packages: you simply drag&drop the package to the "programs" folder, and it's automatically installed.
Even more, all programs works as if they were compressed ISO images or something like (the programs are "mounted"), you can indeed even not install the package, just run doing double click from whatever it happens to be, and the programs run.
There is something simmilar on linux also, called
Klik, but it's not so well known.
Windows users have the worst time about installing programs, every program is distributed in different ways, there's almost no standard, and the only thing more or less popular are installers using MSI-like interfaces, needing lot's of clicks and next next to get something installed. This is obvious not the way to go.