Stress

When it comes to words in fictional languages, how do you feel about stress markers? Do they make a word easier to pronounce or do they make it seem more intimidating, especially if your native tongue does not make much use of them, as is the case in English? 

The words of some fictional languages, like those of Edgar Rice Burroughs's Barsoomian, include no stress markers. Others, like those of M.A.R. Barker's Tsolyáni, are riddled with them by comparison. Because I have become familiar with the pronunciation of Tsolyáni, I don't find its use of stress markers to be off-putting. However, I've heard from many people that, rather than aiding pronunciation, they contribute to the sense that Tsolyáni is difficult to pronounce, which in turn alienates people potentially interested in Tékumel.

I'm currently working on a project that includes names, words, and even occasionally whole phrases from a couple of fictional languages. I ask again: would you find the use of stress markers or other types of notations ("accent marks") helpful or simply discouraging? Do you prefer, for example, "sha-Artan" or "sha-Artán?"