For mellow puffing or spliff additives, it is quite excellent. Also, tobacco is an MAOI (short acting and only MAO B for the most part)... but it does potentiate spice and other entheogens. A light changa cigarette when up on a disso is a glory to behold.
If you haven't tried Mapacho / wild tobacco (the rustico variety) it is pretty sweet compared to your typical domesticated stuff... even organic roll-yer-own. The flowers (hard to come by) from the wild tobacco are pretty psychedelic in their own right.
However, for real changa blast offs, it tends to be too harsh for most people... even regular tobacco smokers. Certainly there are those of us who could manage to take serious lungfuls and not burst into a coughing fit. But for general purposes, easy to toke herbs tend to win out. Mullein as a base is tops... damiana has some strong points for taste and ease of smoking. And, of course, caapi leaves rock for that MAOI kick.
At any rate, you have to know your lungs and your fondness for various herbs in a smoking context. There are a plethora of interesting candidates and they all bring something slightly different to the table.
"Curiouser and curiouser..." ~ Alice
"Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders. Do not believe in traditions because they have been handed down for many generations. But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it." ~ Buddha