I hate to see this post drop off the page without others getting a chance to see it... If you haven't you should google Sparkman & Stephens. This is an old an venerable design firm. On Sailboatdata.com you will likely find at the bottom of the page for the Swift 40 a link to other designs by this firm. See here:
http://sailboatdata.com/view_designer.asp?designer_id=12.
I feel safe in saying a boat designed by this firm has a good pedigree. Builders who have used these designs are Swan and Tartan. Different builders will have different quality standards depending on their market focus.
The Swift appears tubby to me. But that may be what you want. It will not have the room that a modern 40' boat will and it will be more slow. But if well found, I'd guess it could take you where ever you want to go.
You might be able to find more info on the North Star 80/20, which according to SBD is the same design.