I doubt Volvo's changed its location as the car has stayed mostly unchanged since day 1. Now, if it were my car, I too would go aftermarket and it should do OK BUT from what we're told by Volvo people, if one removes the original radio unit (and related equipment), one should then "theoretically" remove its software from the network to avoid network related problems (like false codes when checked, etc). I believe it should function OK but by the cars networked design, it's suggested to do that.
What would I do? I'd probably try it w/o a trip to the dealership first and see how things go. If no problems, I'd be happy.