@BobusX:
Reading your post was depressing.
As I don't have in any way that kind of experience with Descent, I can't understand your exact feelings, but I gather that they are very strong. Try playing it as a hero. Maybe you'll have a different perspective, even as an OL.
As my fellow players are very good as heroes and still I can manage to win as OL, I don't have the same feelings about the game. Still, being this such a good game experience, why don't you try (if you really like playing as OL) to discuss with them house rules that let you enjoy more the game. You could try one, some or all of these:
1) Your monsters can steal equipment. If you knock out an hero and there isn't another hero adjacent to the knocked out hero, a monster can spend one action and steal an equipment. If the monster is able to leave the boardgame with the equipment, the equipment is lost for the heroes. If the heroes kill the monster, they can recover the equipment spending an action.
2) You can choose a lieutenant in the begining of the campaign. You can choose a class to add to the lieutenant. Every scenario that allows you to put an open group, you can choose to field the lieutenant instead. Every scenario that you use the lieutenant and win the scenario, you can give him a XP. You can spend a card to heal 1 point of damage to the lieutenant. Every equipment that was stole by the monsters can be used by the lieutenant. If the lieutenant looses all damage he's knocked out. You can use a turn to heal him 1 red die. The lieutenant has 3 points of fatigue.
3) The lieutenants boost the monsters near them. The monsters 4 squares near the lieutenant will have +1 damage and an addicional brown die.
4) The OL Avatar. At any moment during the scenario you choose one monster to become your trusted commander or the avatar of you . That monster gains the following traits. +5 wounds, +2 damage, +1 yellow die, can make 2 attacks and has two special powers: Despair: Spend 2 surge and give the hero two stun cards and Teleport: spend 1 surge to move the avatar five squares away from his initial position after the attack.
I hope this helps.
One final thought: I play my games with my friends and family the way we want them. If we like them and they are slightly broken, we fix them. That is choosing the FUN FACTOR. All else is unimportant regarding gaming. IMHO.