Due to it's design, slope tent can be seen at event that only use in a single side, like our classic pasar malam! With one end that is taller than the others, it is often use for the "business" side. In case of a wet weather situation, the tent will naturally guide the water down the other end! It is often also used to extend shelters along walkway of HDB or houses as well! It's greatest advantage is that it can be built in a short amount of time (2-3 hours) and it's cost effective!
It does not have an "advantage" per se, compared to the other tents, but rather based on your different needs and requirements. However, it certainly have it's strong points such as easy and fast quick set up, fairly affordable and customisable!
Due to the unique structure of a slope tent, one of the end is taller than the other. This is to prevent water retention on the top in case of a wet weather situation. Some also make use of this unique structure to make the taller side the "business" side as the opening is larger.