The Poecilotheria is a genus that is referred to as 'Old World". Meaning they come from Asia, Africa,etc. rather than the Americas,Mexico,etc. They usually don't have urticating hairs (maybe none do, but I think at least one species does) and have a more potent venom. Thy tend to bite first and ask questions later when feeling threatened unlike the 'New World' T reputation. Arboreal in nature, and among the most beautiful T's in the world. I have none and won't. There are many on here that can give you more info.
As well they tend to be a bit more flighty but that could be argued. Additionally, as many keepers will tell you they have the ability to 'teleport'. Their speed is nothing short of incredible. I have a Poecilotheria miranda that when I was rehousing, I opened her container and she ran all the way across the room before I could even blink. Until you are confident you can manage something so fast, with higher than average venom please wait.
They are some of the most beautiful T's there are. I have 5 different species and am hoping to acquire one of each (that are available in the pet trade).