Installed it this afternoon. It's hefty, somewhere over 1 gig so make sure you download it to itunes and then sync first. They recommend having almost 2 gb free for the install.
I've done some limited testing around my area tonight and so far so good. I'm running on a 3G phone and the load time is acceptable. I was expecting much worse load times after reading some blogs. For my use as a pedestrian while visiting new cities it will be fine. There may be some slight lag moving around the menus, but its very minimal and nothing that gets in the way.
I stood outside for maybe 30 secs after booting the app to make sure the GPS locked in. I'm used to this as I use RunKeeper daily (it uses the gps to track runs, quite well I might add). I walked around the neigborhood tonight with the iphone in hand and the app running, just showing the map. It kept pretty good tabs on where I was. I then set it to "take me home" and it did, very accurate.
It can be run in 3d mode or not. I prefer the 2d overhead view. The 3d is cool but it's a little hard to read the street names. I read somewhere this may be addressed in the next update.
The POI work pretty well, the schools, parks, corner stores were all listed around my area. Showing what's "near me" is only a few clicks away. Seems a click or 2 could be streamlined out but it's not a huge issue, I'm not driving, just walking in most cases so it's ok to stop and click away. I did notice one gas station by me was clearly in the wrong place on the street. I will test tomorrow letting it guide me to that station to see if it is indeed off. Every other POI around me appeared to be bang on to where it should be. Some even have their actual custom logos, BestBuy for example has their logo, kinda neat.
So far for my $69 I'm happy. I have a Garmin Nuvi that I'll continue to use on road trips in the car but this app on the iphone will be super handy when on foot in new cities or even downtown here in ottawa when looking for the closest atm etc. I'm running a Rogers PayAsYouGo sim in my iphone so I don't have a data plan. With this app having everything loaded into it and not needing 3G data transfers it works out really well for me.
I'm going to try out a few more tests tomorrow and report back. So far so good though.