Between the BeoSound 4 and the BeoSound 3000 I would take the latter every time. In my opinion, it is a design classic. However, I should mention that I have owned a BeoSound 2300 in the past, which gave me so much happiness for many years. It did not play MP3 files or take SD cards; only radio and CD but my, what a statement it made. It had a smaller round piece of glass clamping the CD opposed to the larger one used on the later 3200 systems. If you took MP3 and SD cards out of the equation I would definitly suggest hunting down one of those. It was a magnificent system until the BeoSound 9000 came along which was even more magestic!
Thanks for this post. You are taking me back to the days of Bang & Olufsen products that were the absolute dreams of the range for me. All of these products have firmly established themselves as top B&O design, form and function classics, totally unsurpassed, so you couldn't go wrong. Before signing off however, I must be honest and say that there is a certain 'something' about seeing the BeoSound 4 wall mounted, but I still don't think it has anywhere near as nice a design as the BeoSound 3200 and earlier models.
At the end of the day, follow your heart. Best of luck!
Simon.