Demigod does not have serious balance issues.
I stared at the computer, thinking, for 5mins... trying to figure if you are right or not. You probably are, bc u said serious.
I will try to stress out a little more about DG balance stuff.
As I said in a previous post somewhere else, DG has a lot of variables to concider when talking about balance.
Lets get HoN (I'm not a DOTA player, so I will stick with HoN) as a counter part. HoN has mainly 1 playable map that is 90% of the time played 5v5. So they have to mainly balance the game aiming this scenario, 1 map for 5v5 action.
DG. Has a more viriety of maps, and the "worst" part, the game is played 1v1 to 5v5. and A LOT.
The game is very well balanced for 5v5 matches, I would dare to say. What I mean by balance, you may ask.
Well, in a 5v5 match you can chose any DG, and it will be a good pick.
In a 2v2 match, you can't. It will depend upon the map. Prison? There r 2 teams that are superior: LE + Oak and UB + Sedna. Anything but those picks are FAR inferior. So you don't have balance on prison games. 3v3 Matches on prison? Same deal, no balance.
Well, mainly, 2v2 matches, and 1v1 matches wont be balanced. On any small map (crucible, cataract, prison). Those matches you can't play TB or Regulus... and probably not Rook, and prolly not QoT.
On 3v3 matches there are some picks that r inferior (not useless): Regulus, TB.
So, DG is balance for 4v4 and 5v5 action. Or you may say that there is balance among DG since you play each DG on his particular map. Like, Regulus is a good pick at Levi. Each map is for diferent builds and diferent DGs, but DG is not balanced overall.
Hope I made myself clear. For those of you that doesnt know, I'm a brazilian, so, sorry for my poor english