Question : VSTO Question(s)

I have VS 2008 Standard and I can in theory create an addin for Excel (or other office apps) using the shared addin template and following instructions like these
http://support.microsoft.com/kb/302901

How does this differ from creating an addin using VS2008 professional with the full VSTO stuff included?

I guess the nub of the question is
What are the arguments for upgrading to professional if I intend to create an addin for Excel.

FWIW I am planning to create an addin that can use the MS chart controls available to VS ie user highlights some data, presses button, is presented with some options ( Chart type, otions for that chart type, titles, legends etc.) - a chart is produced from the highlighted data and can be saved in whatever is an appropriate format.)

Am I going to find this significantly more difficult if I don't upgrade?

TIA

Answer : VSTO Question(s)

VS2008 Professinal has wizards that automate the process to create the add-in project and the windows installer/ click once deployment if required. Furthermore it uses a technology called VSTO version 3.0 that it is only available for the professinal edition.

http://en.wikipedia.org/wiki/Visual_Studio_Tools_for_Office
http://msdn.microsoft.com/en-us/vsto/default.aspx

Note: Your link is about implementing using COM which is far more difficult/time consuming