Here are a selection of prominent problems, glitches, and just-plain-annoyances with the iPhone 6S, and some possible solutions to them.
Some of them don't even involve resetting.
iOS 9.3 links hang
Apple released iOS 9.3 in March, bringing with it a couple of notable glitches. While older devices seem to have born the brunt of these bugs, the iPhone 6S isn't exempt.
One particularly tiresome glitch relates to web browsing on the device, wherein some have been unable to open links in Safari, Messages, Mail, Notes and other apps.
Indeed, not only do said links not open, they often crash or hang the app.
Some have suggested that this bug could be related to certain third party apps. We've seen Booking.com referenced, but it's not alone. Apparently, simply uninstalling the offending app doesn't fix the issue.
More specifically, it's claimed that this could be an issue with Universal Links, which were introduced in iOS 9. The feature allows you to open links directly into an app.
In terms of a fix, we're afraid its a simple matter of waiting it out until Apple supply an update. Fortunately, the company has revealed it's aware of the problem and working on a fix right now.
Poor battery lifeIt's an age-old complaint with iPhones, but the iPhone 6S has been criticised more than usual in some quarters, thanks to the fact that Apple actually shrunk the battery from the iPhone 6.
Your mileage will vary, and if you're a light to medium-intensity user (as most are), you probably don't have a problem with how long the iPhone 6S lasts between charges.
But, if you are experiencing unusually short battery life, it's worth investigating the usual culprits.
Most of the time, short battery life is down to a wayward third party app churning away in the background. To determine if this is the case, and which app is to blame, head into Settings>Battery.
Scroll down to the list of apps and see which is on the top. Social network and news apps are often to blame here.
Once you've identified the culprit(s), you have a couple of options. The easiest way to end their power-glugging ways is to delete them, but that probably isn't ideal.
To lessen their impact, go to Settings>General>Background App Refresh, and toggle the offending app to the off position. It will now no longer remain active in the background, so you won't receive updates. However, you can simply dip into the app when you have a spare minute and refresh manually.
Your battery life should get a massive boost.
Also, don't forget Low Power Mode. When your battery life is in the red, or even when it isn't, head to Settings>Battery and flip the Low Power Mode toggle to on. This will scale back things like background app refreshes, Mail fetch, and some visual effects until you can get to a power point.
Regular crashesApple has shored up iOS 9 since its release, but some people might still find their iPhone 6S crashing on a semi-regular basis. If so, your best bet before making that Genius Bar appointment could be to attempt a complete wipe and restart.
First, ensure that your data is backed up by tapping Settings>iCloud>Backup and ensuring the iCloud Backup option is flipped to on. If you want to be sure, hit the manual Back Up Now button and follow the procedure.
Now erase your iPhone by going to Settings>General>Reset and selecting Erase All Content and Settings.
You'll eventually find yourself right back at the Hello screen you encountered when you first turned your iPhone 6S on. Set up according to the instructions, selecting the Restore from iCloud Backup when the option presents itself.
Still encountering the same unstable performance? There's one other process you can try which involves essentially starting from scratch. Reset your phone as above, but don't restore from backup. You'll lose all your app data, but you may just solve the problem.
Overheating issues What recent flagship smartphone doesn't run into the odd overheating issue with some unlucky users? None that we can think of, and the iPhone 6S is no exception.
At launch there were some reports of iPhone 6S handsets that literally grew too hot to handle, even when not doing anything particularly strenuous like playing a 3D game or streaming a long HD video. Others claimed that the Home button, in particular, was growing uncomfortably warm to the touch.
If either of these complaints applies to your phone, it's probably a hardware issue. In such a case, taking it into Apple and getting a new handset is your only course of action.
There are a couple of things you can try before that, though. First, apply the advice we gave you in the 'Poor battery life' section, and check for rogue apps.
If an app is seriously hitting your battery life (we're talking 40 percent or so), it means its using your iPhone's internal resources more than it should, which will inevitably result in greater heat build-up. Kill it.
Failing that, you should also follow our advice for the previous section and reset your phone.
3D Touch not workingThe biggest new feature of the iPhone 6S is 3D Touch, a pressure-sensitive screen technology that provides things like link and email previews and snazzy Live Photos activation.
However, some people have found that the 3D Touch feature doesn't work on their iPhone 6S. If this is the case, there's nothing for it - you need to take your phone into Apple, which will probably replace it for you free of charge.
Just for peace of mind, though, go into Settings>General>Accessibility>3D Touch and make sure that the feature is actually turned up. Wouldn't you look silly at your Genius Bar appointment if it wasn't?
You can also try tinkering with the sensitivity of the 3D Touch system from here. It could be that you're simply not getting the right pressure, so try moving the slider to Light.
GPS not working properlyHave you found GPS performance to be spotty on your iPhone 6S? Some have.
It's been speculated that this could be an issue with certain 4G networks, with some LTE bands seemingly interfering with GPS reception.
If so, try going into Settings>Mobile Data>Mobile Data Options>Enable 4G and select Off.
Failing that (oh, go on then, try a reset too), a visit to Apple and a new handset is your best option.