Shaktimaan89, (and whoever else),
Sorry for taking so long to reply. I share your feelings about iOS. I was reluctant to take the chance and upgrade to iOS 6, given how slow my iPod already was with iOS 5.1.1. Fortunately the devs at Apple seem to have given some thought to lesser devices, because my good ol' iPod touch is a perfectly smooth and capable device running iOS 6.
Unfortunately, I did not take any performance measurements on my iPod running ios 5.1.1, so I can not do a direct comparison. Here are some stats for iOS 6.0:
With no apps running in the background, it loads:
-the music app in 2-3 seconds
-the settings app in ~1 second
-reminders app in >0.5 second
-clock app in >0.5 second
-photos app in ~1.5 second (I have about 1,000 photos)
-camera app in ~2 seconds (from tapping the icon to the shutter opened)
-Angry Birds in ~11 seconds
As for multitasking, all I can say is that it's about the same as it was as far as I can tell.
The one big improvement over iOS 5.1.1 in my opinion is SpringBoard (the background application that runs the home screen, lock screen, and basic animations). In 5.1.1, if you had a lot of apps running in the background, the home screen would sometimes freeze when swiping between pages, the unlock animation and other animations would drop frame rate drastically, etc. Not so in iOS 6. SpringBoard seems to have been given top priority. All animations are smooth and fluid just as they should be.
The one thing that's not good is the App Store. It has a whole new look and UI, but it crashes a lot. Which is kind of a big deal, because the App Store is the app that you use to install apps. For a temporary fix, go to date & time settings and set the date a year ahead. For some reason, this should make the App Store work a little better.
So in my opinion, by upgrading to iOS 6 you'll get a lot of cool new features, and performance will be as good or better than before.
I hope this helped,
-Asa