iOS 9.1 slowed down my iPhone 6 Plus leading to unsatisfactory experience

No, that's not normal behavior. What troubleshooting steps have you taken? Have you restarted? Done a forced restart (used to be called a reset). Restored your phone from back up? Restored as new?

How much free space do you have on the phone? Do you have Background App refresh enabled for a lot of your apps? You may want to review that list as too much updating in the background could slow things down.

I Have been having same lag issues and so much more. Especially with touch registering right away. Everything was great until update. I posted all my issues in this forum yesterday and no replies. I've been an iPhone user since 4 and have always been so happy. I'm extremely disappointed. I switched from Andriod because of issues like this and after all these years not having to deal with this stuff it's even worse. Ugh

Background app refresh has nothing to do with downloading things from the App Store. It's enabled by default. Go to Settings>General>Background App Refresh and turn it off for anything you don't feel needs to be updating its data in the background. It will increase your battery life as well.

If a forced restart and turning off Background App refresh doesn't resolve your issues, the next step would be to restore from a back up. If that doesn't help, restore as new and test the phone to see if, with nothing on it, it works properly.

SadieKitten wrote:

I Have been having same lag issues and so much more.

So, follow my suggestions.

HI! Thank you, I greatly appreciate your response! Yes I have done all those steps, many times unfortunately. Not the restore as new. otherwise I have every app option, and everything I can possibly running as minimally as I can make it. I was resistant about it at first but I did relent and turn off everything I could find that could run unnecessarily and have even deleted many apps. I obsessively end apps as soon as I finish using them, I never have things just running. Meh.... Anyways, thank you again!!

SadieKitten wrote:

I obsessively end apps as soon as I finish using them,

That will slow your device down. Stop doing it.

Then it's time to restore as new.

well, that's confusing, I thought leaving apps running all the time would slow the phone down. When I say endin I mean I double click the home button and swipe up. Also, do you know what would cause me to need to restore the phone?

I Should add... The reason I ask is so I know what not to put back on the phone, or at least the potential issues. The main thing I don't understand is why everything was fine before updating. What could be causing all this trouble when nothing had changed except the update. What could be causing the conflict? I don't want to go through restore, putting everything back onto the phone, just to end up with this issue again.

SadieKitten wrote:

well, that's confusing, I thought leaving apps running all the time would slow the phone down. When I say endin I mean I double click the home button and swipe up. Also, do you know what would cause me to need to restore the phone?

Those apps are not running. They are simply recently used. They are frozen. Forcing the phone to relaunch them completely every time you want to use them uses battery. So, unless you enjoy flicking them up (some people do), stop wasting your time doing that.

Things go wrong with technology. The only way to test if the problem is with something you put on the phone or with something inherent in the phone is to wipe it back to factory state and test it. No, it may not solve your problem but it might and the only way to find out is to do it.

SadieKitten wrote:

well, that's confusing, I thought leaving apps running all the time would slow the phone down. When I say endin I mean I double click the home button and swipe up.

Right, and don't do that. Force-quitting apps is not recommended and is completely unnecessary. The only time you should do that is if the app is acting up in some way. Apps that you've used recently are completely idle and not utilizing any resources, so force-quitting them actually consumes more battery than just leaving them be.

SadieKitten wrote:

Also, do you know what would cause me to need to restore the phone?

A corrupted backup, so restoring an putting that backup back on the iPhone just perpetuates the problem. Restoring as new (no backup) is likely the solution if you're still having troubles after restoring and loading your backup.

LOL wow.... Guess that's what I get for getting my info from T-Mobile people.... Omg. That is NOT what I was told in any way. And thank you both, that all makes complete sense. It's not like I haven't been told to restore, but no one could explain to me why and it's hard for me to just do something without having at least somewhat of an understanding what and why I'm doing it. Corrupted backup makes complete sense after reading about that. I suspect that's exactly what it is. Thanks so much!!

SadieKitten wrote:

LOL wow.... Guess that's what I get for getting my info from T-Mobile people.... Omg. That is NOT what I was told in any way. And thank you both, that all makes complete sense. It's not like I haven't been told to restore, but no one could explain to me why and it's hard for me to just do something without having at least somewhat of an understanding what and why I'm doing it. Corrupted backup makes complete sense after reading about that. I suspect that's exactly what it is. Thanks so much!!

It's a very common misconception. And, I think, sometimes people who don't want to take the trouble to really explain things, tell you something to do that makes you feel like you're doing something.

Restoring is a bit annoying but probably less annoying that the problems you're having.

Best of luck.