I had the refined farming work better sometimes - not always. I haven't actually compared the before/after to know if refined housing is the same way.
The way that I read it was based off of my GalCiv experiences. That is, each refined tech increases the associated ability by a percent. So refined housing may only add +15% or something, so ti won't appear to be a wholly massive increase. But, then again, I could be totally wrong : )