Thanks frying_fish. I knew sab was python (didn"t know sickbeard was - only just discovered delights last week, don"t know why left it so long before installing). Until you put it so obviously I still had it in my head that it would be a difficult task because of the processor to recompile (think I"ll be adjusting head when start using).
Personally I don"t think I"ll be impacted by downlod speeds as I max out at 187 kbps on my free bt usenet account, (hence interest in low powered always on device). Memory wise sickbeard and sab consume about 33,000 kb each on my Windows device (I know oranges and raspberries but no better fruit to compare with) so will be fine till I open opera at 168,000 kb
The unpacking could be painful. The viewing of mkv, I fully expect to be diabolical even though other formats will be displayed with grace and ease (why I was thinking of handbrake), if I"m wrong it"ll be a nice surprise but will leave me working out conversions for tablet.
Actually, the unpacking would be worse than the mkv playback, depending on what encoding the file is. If the file inside the mkv container is h.264 then it should be fine as that can be decoded in the GPU (from what I've read anyway). It is the unpacking using up all the RAM and lots of writes to the SD card I would be concerned with (unless of course you hooked up a USB HDD and had that as the processing directory). Thankfully the use of python would be handy, but would have to remember to use python 2 not python 3 I think.