It's just a PDF.
After reading
thisI'm just going to do my first playthrough IWD-style. Once there's a fully-functional tool to give the companions decent starting stats/builds, I'll play it again and use the companions all the time. I assume that I'll be able to grab a particular companion and do their story quest stuff even though they're just sitting in the stronghold all the time, so all I will really miss out on is conversation and banter type stuff the first time through.
It's slow but not *that* slow. Not sure how long it took exactly because I left it unattended for close to an hour, but I doubt it took more than 15 minutes or so. Glancing at the GOG forum it looks like some people had issues with anti-virus programs hanging the installer. I don't run anything but Windows Defender on my game PC.