The official win32 gimp installers were not made by sourceforge, but by the GIMP contributor now locked out of managing the relevant sourceforge account. The same win32 installers that used to be provided on sourceforge are now provided from gimp.org directly http://download.gimp.org/pub/gimp/v2.8/windows/ the problem is the nice binaries being replaced by sourceforge made installers that also install adware.
wget at least isn't affected, as long as you copy the link from the files page (the one that normally displays ads and a countdown timer in browser - it'll download the file directly with wget, since they apparently do user-agent sniffing).
What does the SourceForge shell access get you? If it's only the ability to edit your website and maybe your code (and not install, compile, etc. things), is it valuable in a world with git-push-to-deploy and with web-based editors?
Trivial, technically, but can still be an unwanted cost for projects that push a lot of bits out. Our software at SF.net burns through several terabytes of bandwidth each year for several million package downloads. We've always appreciated their network of mirrors. But, it seems like it's time to move away from SourceForge.
We already relocated our revision control to github (though I'm considering another move to a self-hosted thing on Phabricator or gogs or gitlab, as I'm more cautious about using third party services for this kind of stuff these days).
The thing is, it's not exactly "their" network of mirrors. They mostly rely on third-party mirrors run by universities and other organisations that offer mirroring for free to a bunch of major open source projects and sites.