Lap sealant! hands down, Lap sealant!!!
I have used both, and both are excellent, and the tape is incredible in its holding ability.
I have used both for enough years that I have had to remove both many times. The tape is a nightmare to remove, requires a heat gun, and always leaves a residue or "stain" of stuff that is hard to get off. Sometimes it comes off clean for a few inches, then other times it sticks as a mess.
Lap sealant comes off with a scraper or putty knife. Leveling lap sealant flows into all the nooks and is much better sealing odd shapes where the tape will never seal. Tape only seals flat surfaces, where two surfaces meet (like the vent flashing) you will need a bit of lap sealant to keep tape from leaking.
Tape should only be considered when you need that extra strong bond. IF you can make lap sealant work then use lap sealant.
