64-bit add-ins can offer improved performance in some cases: particularly where the amount of data used is huge, whether the data is contained within the spreadsheet or is used within calculations external to the spreadsheet.
XLL+ now creates both 32-bit and 64-bit builds of XLL add-ins, so that you can now provide your add-ins to users of Excel 2010 64-bit edition.
All the XLL+ redistributable run-time servers are now provided in both 32-bit and 64-bit formats.
The XLL+ AppWizard now creates projects that can be built as 32-bit add-ins or as 64-bit, or both.
If you have existing 32-bit projects built with earlier versions of XLL+, you can use the XLL+ Upgrade Wizard to convert them to XLL+ 7 projects, with 64-bit support.