My only experience is with the Alpine.
It has strong iPod interface. Not sure about the Pioneer's.
As mentioned by j3bus2k3, the PXA-H701 is needed to get anything resembling tuning but the PXA *is* a heck of a strong tuning tool. The IVA-W200 preout is a paltry 2v but the PXA raises it to 4v.
Besides just DVD video the Alpine does DVD audio as well. As you know, nav for the Alpine is waaay expensive.
x2 on the PulseTouch.... Superficial yes, but all of us like the coolness factor in our toys, no?
If you haven't already, you may wanna look at the Eclipse units, they appear to me to be good value relative to a 'comparably equipped' Alpine. No XM radio on them though, just Sirius.