As a player I never have fun fighting beholders. Playing the game of course you must accept monsters attacking you, and they will have nasty attacks sometimes. However, even against a dragon the breath weapon is bad news but otherwise its melee attacks are standard fare for warriors if on the upper echelon of power. With beholders every attack is save or suck. For me there's no fun in facing the danger. I want the combat over with and at least one PC will drop if not outright die. It's too random whether you live or die.