Should the update to IOS 5.1.1 on an iPhone 4S NOT be done at this time?

If your phone isn't hacked or jailbroken, there is no reason not to update.

Users have complaind about & reported problems with EVERY SINGLE iOS update since the original iPhone was released...EVERY SINGLE UPDATE.

Apple has sold millions of iPhones & millions of users update with zero issues.

I have updated two phones and two iPads and don't have any problems

I have an iPhone 4 and I'm having a lot of problems just now that I've updated to ios 5.1.1. The phone doesn't ring, messages just go to voicemail with no notification in most cases. I have to push the Home button several times to get the phone to respond when it's asleep, and it responds slowly even then. All in all its becoming annoying, which is why I searched for ios 5.1.1 problems, which led me to this post. I would suggest not updating yet. Wait for ios 5.1.2. The problems that I'm having all started exactly when I updated to 5.1.1. I was having no problems before that.

Been running 5.1.1 flawlessly

I see you think iOS 5.1.1 is causing problems. You need to:

1. Read this: http://www.nizkor.org/features/fallacies/post-hoc.html.

2. See Appendix B and learn how to troublshoot your iPhone: http://manuals.info.apple.com/en_US/iPhone_iOS4_User_Guide.pdf

Those problems are just a bunch of hype. Nothing to be concerned about, you won't have any issues. I'm not saying it's flawless, but these "issues" are often beaten to death.

You can't update on AT&T network - only over Wi-Fi, anyway. Besides it would be a horrendous amount of data on your AT&T plan so Wi-Fi is better.

The best way is USB connection to iTunes on your computer, first backing up the phone.

But, it also eats up your data.

Incorrect. When updating via iTunes, all the data arrives to your computer via your ISP, and then is transferred directly to the phone via USB connection. There is no use of cell data at all. It's the same as if you updated by WiFi.

You're confusing different things. Just plugging into the USB port does nothing except charge the phone - it otherwise functions independently, using cell data or WiFi as configured, and cell data may be used. You can't use the USB connection to surf, get email etc. WiFi is for that.

However, when updating, restoring, or syncing the phone via USB, that data is transferred directly to/from your computer over the cable and does not use any cell data.