Sorry, should have thought to link it!
http://www.androidiani.com/forum/letv-x500/492828-modding-letv-x500-twrp-firmware-powered-bb72.html
Would advise Google translate unless you're very clever and brave!
There's a "grossoshop" version of twrp which is the only one i managed to get to work. Worth the bother though.
I used the 5.5.009s "aroma" rom here, but between the two links it was borderline easy!
http://blog.grossoshop.net/come-installare-rom-bb72-su-letv-x500/
Mild-moderate faff, but well worth it. No chinese silliness, no DU battery saver idiocy. It's 5.5.009S now, so all the fixes so far.