Lots of article and blogging setups in XF. There is no reason that even the Xencarta wiki can't be one, let alone the blogging add-ons.
WP can be customized - but that requires time and/or expense. As it stands (stock), it's more of a blogging platform.
I have to somewhat agree with DRE. Unless we had a perfect and constantly upgraded add-on (from XF themselves, open source with multiple authors, etc.) a XF-only setup would be best for most IMHO. That way your system is better integrated and secured.
The main thing I see missing from the XF solutions is reasonable placement of images - captions, word wrap, etc.
Give me that and maybe simple pagination for up to 3 pages and I'll bite!