I am looking at getting away from Android (have a Nexus 5) and going back to iPhone (had a 5 when it came out). That being said, I don't need the latest, especially when it comes to iPhone. Unlike Android, in my experience it doesn't slow down as it gets to be a year or two old. So, I'm looking at getting the iPhone 6 64GB when the 6S is released, mostly because of the price drop at that time. If the 6S is somehow much much better, I might just get that instead. So here's my main question: within a week of the release, will I be able to walk into my local T-Mobile store and expect to be able to walk out with a new 6 in the 64GB configuration? Also, have iPhones changed since I last used them in that they will be slowing down faster than they used to? My Android phones all slow down within months of getting them, and I don't want this again.