It depends on the definition of "mostly". It is broadly similar but utilises a newer, faster, broadcom SoC. If the tuners are the same then it is likely that the HDR Fox software could be made to work on it but would require a lot of work to replace the bootloader. Particularly if Humax have password protected or disabled the JTAG interface (as they are required to do by the YouView specification..).
If the newer SoC is a different architecture (ARM instead of MIPS) then there is no chance, but I believe that all of Broadcom's PVR SoCs are still MIPS.
The first reply from Gomezz - although presumably accurate was unhelpful. Perhaps he was having a bad hair day.
Yours, Sir, is much more enlightening. Obviously I know zilch about Unix programming, or how much microcode is stored where one can get to it. Doubtless other minds have looked at this kit and possibly gone away disappointed. Hence the silence.
If one doesn't ask questions, then you don't get answers.
I was looking for an inexpensive box as a spare before the bubble bursts. It's a shame that the hardware model is good but it has been emasculated for marketing reasons. A Google search shows that A.Sugar had something to do with YouView and history shows his work is often a triumph of marketing over function.....