I downloaded the the first beta last week on an old 5S.
This is an early beta, but a lot of the general navigation improvements are dependent upon 3D Touch, which is only on the latest 6S hardware.
All the incremental improvements listed below are contingent on having 3D Touch:
- Expand homescreen icon widgets
- Expand lockscreen widgets
- Clear all notifications
- 3D touch to reply to rich homescreen notifications
- Raise to wake homescreen (not 3D touch dependent, but currently limited to 6S hardware)
Taken together, all of these improvements make it easier to use an iPhone--and they won't be available to use on older hardware due to their lack of 3D Touch.
Several commentators have been cool toward 3D Touch, but I have appreciated using it as a way to quickly enter the portion of an app you want to use. It's especially useful to 3D Touch the Voice Search shortcut on the Google app and run a quick voice search, for example. 3D Touch in apps like Tweetbot 4 make opening links and media better as well. I use the function every day.
Commentators aren't the only ones to cool toward 3D Touch. Developers have found uses for homescreen shortcuts, but little else. It's intriguing to see Apple take matters into their own hands and lead by example when it comes to 3D Touch, after spending a few years expecting their developers to iterate and not rapidly developing their own first party software.
Here is The Verge's first look at the beta on newer hardware: