One Thing Demigod Is Under Rated For!
Which is the fact each Demigod has 8 different skill trees.
After playing LoL for a week...the fact there are about 36 heroes is awesome. But the each time you pick a hero you have to basically go the same skill build is quite depressing after playing Demigod. Even if there were 1000 heroes in LoL the heroes themselves still wouldnt be as diverse/fun/replayable as Demigods are. The fact I can start a DG game up with any character and then go to my self and say "hmmm which build I should take" is awesome.
However, the one thing that kills this huge bonus DG possesses is the items. In LoL - although my hero build has to be nearly-identical each time - the amount of different item builds I can do can certainly make up it. If Demigod just had more viable items/more interesting items/a larger amount it would kill LoL depth wise. (not to mention Demigod has 8 maps, generals, flags and citadel upgrades).
Because of the items/connectivity/features that LoL has though it still beats Demigod depth wise. We just need
A ) More Items
B ) More Viable Items
C ) More unique AND viable items
After that the only thing Demigod doesnt do better than LoL imo is connectivity/features (which is really important)