Hope it turns out great for you. Keep us posted.
The data I include in the recipe is from Beersmith.
Differing boil-times and alpha acid content will impact the estimated IBU's the software calculates. My numbers are correct (insofar as they are an estimate based on data available to me)
I wonder why there is so much of difference? I used the same ingredients.. except i didnt use the Saaz hops as I only had the Hals.