I'm shocked how fast the UI is. I'm on an iPhone 4S and every UI gesture, view load and transition has absolutely no lag. For example, from the sliding info sheet, tap on the street view button and it loads instantly.
Even requests that are hitting the server seem to return almost instantly.
Looking at the UI I can see why it's fast - everything is set up in a way to maximize performance if you're willing to put in the work.
Which is to say, simple text, simple lines, simple shadows - all of which, so long as you take the time and draw smartly using Core Graphics, is well within the capabilities of any iOS device. Combine with a few dashes of smart UI caching and the whole thing will scream.
iOS UI optimization is a topic I wish more devs knew about. So many relatively simplistic apps are dog slow because no one has bothered to do even the most modest amount of optimization.
tl;dr Use Instruments while running on the device (not the simulator) to pinpoint the highest avoidable CPU usage and then optimize the relevant code. Repeat until the scrolling is buttery smooth on a 3GS :)
Could I also ask, lots of people are asking about the FPS. I notice the app seems to have zero hiccups/ latency spikes throughout the UI, however the framerate does seem to be around 20/30 FPS in the map view on my iPhone 5. Is this intentional? It is a very consistent framerate it is just that it is noticeably lower than most every other part of the iOS experience.
I'm on an iPhone 4, and panning around is stuttering quite a lot. I'm looking at the downtown Seattle area in particular, if that matters. I'm wondering if the network speed has anything to do with it. I'm using 3G in a heavy urban area, so maybe it's hanging when fetching server data due to network congestion.
Even requests that are hitting the server seem to return almost instantly.
Is it just me?