We take a spin with Apple's latest smartphone and tablet OS a

This will not be your normal, run-of-the-mill review. In
normal reviews, the product’s fully cooked, to the point
where you can fairly evaluate every aspect of what the
New Thing does.
Since this is a review of iOS 9, we’ll all need to wait a little
while: it now transpires that we won’t be able to play with
its star feature - 3D Touch - until the new iPhone 6s and 6s
Plus reach UK stores on September 26.
For now, let’s call this review a work in progress: be sure
that we’ll update it as soon as a 6s lands in the Stuff
offices in a few weeks. That said, we have spent a very
solid 24 hours testing the GM Seed of iOS 9 (which should
be all but identical to the update that drops on September
16) on our iPhone 6 Plus 64GB.
That’s enough time to know whether iOS 9 is a serious leap
forward for the smartphone experience, or conservative
refinement of an already successful OS. There’s certainly
enough new stuff in iOS 9 to warrant anticipation among
Apple followers - albeit some of it will be hidden under the
hood for owners of pre-iPhone 6s devices.
Apple claims to have pulled off a trick that evades most
upgrades in real-world usage: improved battery life (up to
an hour more, they say, from a single charge) and snappier
performance.
Even if you’re not upgrading to the new hardware, you’ll
see above-the-hood changes from the iOS 9 update - the
new Siri Suggests search screen (to the left of the main
home screen, prompting parallels with Google Now), a new
default font, hefty updates to several Apple apps and the
arrival of Apple News.