Short version:
Noob here. but i made an account just for this:
I replaced two png files in the
media directory and genuinely
HALVED my GPU USAGE!!! 
tested results:
original images: 45fps - 99% gpu usage (maxed
)
replaced images: 45fps - 49% gpu usage (i used an fps limiter here to make a direct comparison.
)
replaced images: 60fps (maxed
) - 65% gpu usage
ram and cpu usage differences remained unchanged
anyone else want to check?
check your fps and gpu usage on wall or multiplex views (the ones with issues for me), replace the two files, check the difference, let me know if i am full of it?
http://i.imgur.com/l7tEz2o.png black.png
http://i.imgur.com/vyB877y.png darkgrey.png
%userprofile%\AppData\Roaming\Kodi\addons\skin.aeonmq5.helixmod\media
------------------------------------
Long version:
ive used aeon nox 4 for the longest time on xbmc frodo, youtube api update forced update to helix. hated that aeon nox 5. found mq5, wasnt able to get it to run at 60 frames per second always on helix, just to see how much the skin was undeveloped. tried mq5 and mq4 on my xbmc frodo, still couldnt run it at 60frames per second. must be me. this comp can play crysis 1-2-3 etc, modded skyrim, etc.
started troubleshooting, picking at xml files checking which views had the issues the most, found a commonality. a 1280x720 solid color picture being used (and scaled) many times, so i shrunk it to a 16x9 pixel and replaced it. POOF! 60fps in that view.
found another view, that didnt get the benefit. checked that one. found another 1280x720 solid color png being used (and scaled) many times as well. i replaced it with a 16x9 pixel solid color in that view. POOF! 60fps everywhere. no more framerate issues at all. it doesnt seem to have broke anything that i can tell, seems absolutely worth it.
testing methodology:
found one buggy area in each affected view, turned off extra stuff to keep things consistant.
used fraps for fps monitoring
used afterburner to ensure gpu clockspeeds remained consistent through all tests
used rivatuner to fps limit, to make a direct (fps to gpu use) comparison in one instance.
relevant specs:
kodi installed on ssd
radeon 5850 (three of them, but it doesnt matter here)
core i7 930 (4c/8t) at 4.0GHz
excessive 1600MHz ram
windows 7 64bit also on ssd
