Note that if Vlad dies by teleporting into a wall, the cape may become unreachable.
Vlad's Cape grants the user double jump and after the second jump also grants slow fall (similar to a regular Cape). When this item is used along with the Climbing Gloves, the player can reach almost any place they want, as attaching to a wall will replenish it's second jump.
Note that a player cannot use their whip and perform the cape's double jump at the same time, due to conflicting animations.
Vlad's Cape also makes enemies drop double the blood when hit (the usual number of drops is two, four with Vlad's cape), making it an extremely useful item when the user also has the Kapala, as it makes farming health significantly easier.
Jetpack vs. Vlad's Cape Debate
In Spelunky 2, not only has Vlad's Cape been buffed, but the Jetpack has been nerfed as well. These factors have caused many players to actually favor Vlad's Cape over the Jetpack, creating an interesting debate between which of the two should be picked by the player. Many factors have to be considered when forced with a decision between the two, and may even be worth it's own wiki page.
In general, many players consider Vlad's Cape to be the lower mobility, high survivability option, as players do not need to worry about it exploding on their back, can reap insane amounts of blood for the Kapala while wearing it, and can decently travel across levels using both it and Climbing Gloves.
In contrast, the Jetpack can be seen as the high mobility, lower survivability option, as players who are able to avoid taking fire damage and can maintain their health properly are immensely rewarded with it's high mobility, which proves near invaluable in places like the Cosmic Ocean.
Because of the advantages and disadvantages that both pack items have, it is typically up to the player's choice of which of the two items they wish to take.