Its true, for me a perfect box would have to be open source, but to others they couldnt care less if it was open source or not.
I used to use dreambox's for years as the GUI is open source, it worked out really well for me and was able to add a few features here and there. But the drivers for the tuner/demod were closed source and I kept hitting a wall when I tried to add new features. Now I use a Linux box with PC tuners and love it. Many people wouldnt consider Linux w/PC tuners a perfect box, but to me it is.
I have blindscan (smart and long), spectrum scan, iq plot, dvb parsing, 4:2:0/4:2:2, H.264, ATSC, DVBS, DVB-S2 qpsk, 8psk, 16psk, 32psk, acm/vcm, turbo-fec 8psk/qpsk, Digicipher II, and working on adding DSS (kinda already do if I use wine/tsreader), I can view locally or stream via tcp to another box. There is very little up there I cant watch/find.
UDL