Same here, though I've been at this for only a few hours total and have to be really miserly with my data usage. 500MB can disappear real quick.
Amusingly, all the Drowzee appear around my work, which explains so much.
Got a number of Stops in close proximity to both work and home, though, so that's a plus. 3 stops near my house are all on the same footpath, even.