I have had really good experience with FWH'ing on a homebrew scale. I typically use the same amount as used for bittering addition with good results.
I find that the beers have an unmistakable hop flavour and a much cleaner and longer bitterness. I have not realised noticable increases in aroma. I now use this procedure on all my styles.
Search the net as there has been quite a bit of experimenting in the homebrew community.
I know promash has calculations for IBU contributions from FWHs. Though I've never had a beer analysed, I am confortable with the calculations versus the results.
On a micro scale, do you guys that do it find it justifies the extra cost?
Jeff Rosenmeier (Rosie)
Chairman of the Beer
Lovibonds Brewery Ltd