Something like 10-11x bigger installer lol. It's really tiny. Don't have a Windows box so I can't say how similar .EXE's, RAM, and CPU usage are.
I'm open for suggestions on how to reduce size.
Anyway, I'm not sure what can be done with Boost: just too complicated. Maybe replacing what you use in it with lightweight alternative. However, you could see if you can replace OpenSSL with LibreSSL. OpenBSD team trimmed out hundreds of KB of fat and problematic code out of OpenSSL when building it. You get better security, too. :)
Note: Mac OS X already uses it. So, it must work decent by now.