The weapons become quickly fearsome with the increase of your marksman skill and with sneak.
My latest character has sneak and marksman as prior, and at a level 25, I took out more or less any daedra with two-four shots and they didnīt have time to attack me. Though Golden saints and higher are excluded to these monsters.. they are just too nasty unless you get a crit
With the official area arrows plugin you can get your greedy paws on a daedric bow
Or boost your conjuration and get bound longbow. 2-50 in base damage I think. There are also glassbows in an unofficial glass extension plugin that adds the glass longbow; 5-35
Dont dizz the dwemer x-bow. It is a great weapon!