Are you a part of this test? :o If so, how quickly are you able to track things? How hard is it to use? Is it causing server lag again?
Hi! I'm in San Francisco now, so now I can finally answer your questions.
Tracking is quick, easy, and intuitive. Nearby Pokemon only show up at PokeStops, so that takes out a ton of guesswork. You simply select the Pokemon on the list that you want to find, and the game shows you the PokeStop where it is located. The tracker will notify you if the Pokemon despawns before you can get to it.
Just to clarify, lures do
not have to be used for a Pokemon to spawn at a PokeStop on your Nearby list. But if you want to attract Pokemon to a specific stop, you need to use a lure.
Nearby Pokemon are extremely common here, but I think that's because of the sheer number of PokeStops. I have 6 Pokemon on my radar right now. It's just a matter of going and getting them.
[Edit] I don't recommend being on a set route, because the new system tends to make you wander and backtrack often.
I have noticed that there is more lag in areas with lots of active lures together. But otherwise there is no lag.
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Another thing that might be worthy of note is that sightings with the current tracker (you get both) are much rarer now. I was able to find and catch about 4-5 Pokemon on the other side of the SF Bay without this new tracker easily. But only 2 Pokemon have shown up on my sighting list in SF.
So, in short: as long as you have PokeStops near you, this system works great. I'm very excited to use it more.