Joomla! Discussion Forums

Since Joomla! itself has decided to use a non-gpl (and non-integrated) forum component, this seems like a good place to ask this question...
I'm starting on the re-development of a site that will have cms, forum, event calendar, business directory, and classifieds elements (among others).  For most of these elements I have a choice between gpl and non-gpl open source programs.  If I go 100% gpl, then I can integrate to my heart's content without violating the gpl.  However, if I go with a combination then I have to be satisfied with modifying liik and feel of each app to be similar, but leave them stand alone.
Any suggestions on what to consider when making the decision to go 100% gpl or not?
thanks,
joe

There can't be a suggestion that would apply to all cases, all users.

End users are not concerned by the GPL vs GPL choice in their choice for extensions, as long as they do not distribute such a package if integrated.
It's then up to them to choose their extensions/scripts in function of the functionalities needed and their will/ability/decision to give a common look to the whole final site.

I have personally decided for a long time to never integrate forums in Joomla as I want to separate db/security matters and facilitate upgrades.
I do not even care about design in some cases and may use Iframes for an apparent integration.
Joomla had chosen to not integrate SMF into Joomal itself from the beginning of these forums and not after the decision on GPL.
It is just a simple personal choice.

The issue is similar IMO to the heated debate that went on around MS Word at the end of the 80s.
From an extremely good text editor (version 5), it became what we call in French a "usine à gaz".
Same when Adobe/Macromedia started mixing image pixel editing with vector/postcript drawing.
i.e. wanting to do all with one app creates more issues than taking 2 specialized application with a few features, but working good.

Therefore, the choice is totally yours.
Hope this helps.

Thanks.  Good advice.  I had considered the likely difficulty of integration, but not the security and maintenance aspects you highlighted.  No doubt I'd have created a nightmare for myself.
joe