Why is my ipod touch 4G unusually slow?

Question

So I have a 4th generation ipod touch. I updated it to IOS 5 from IOS 4.3.5 a couple months ago. It's been really, really, slow and laggy to the point where it's something I despise! I upgraded from 4.3.5 because my ipod was pretty slow and applications always crashed; I thought IOS 5 would fix all that, but, I was wrong!    With IOS 5 my ipod's battery life ***** (I charge it to 100% and then 15 minutes later it tells me there is only 20% left), it's super laggy (closing out of apps is painful and I have lots of problems with the lock screen. The screen freezes all the time), Safari is slow as a snail and so is other web-based applications, and apps crash constantly. Simply swiping from screen to screen is painful!   Then I upgraded to IOS 5.1 hoping it would fix things but...no...
I've tried a clean restore to factory settings, which didn't help at all. I make sure I close the apps I'm not using. I do not have so many apps or music. My wifi/internet connection is quite good. I don't know what is going on!
My ipod is second hand from my cousin and it WAS jailbroken, but not anymore. My warranty is also up. I've noticed other people have been experiencing the same issues but the thing is, my friend also has a 32GB 4th gen ipod touch on IOS 5.1 that runs smoothly and is very snappy and responsive, unlike mine. She has WAY more apps, photos, and music than I. She's had her ipod for longer than I have.
So does anyone know what is going on? Any other ideas? Thanks a lot!

Answer 1

Maybe the solution is that you iPod is slow is because you are not closing your apps after you use them. To do this you must:
1. Press the Home Button to get out of that app
2. You will return to the Home Screen
3. Click the Home Button twice, (do this quite fast, But not TOO fast)
4. A bar with all your apps that you have come out of will be on the bottom of the screen
5. Hold down one of those apps
6. They will start to "jiggle"
7. A little red circle will be beside all of the "jiggling" apps
8. Press that little red circle and those apps will close (NOTE: This is NOT deleting your apps)
9. Now you apps are closed NOT deleted
10. Your iPod will now speed up in: Browsing, downloading, syncing and much more
11. (Bonus) - To DELETE an application do the same thing ( But not clicking the Home Button twice) and all of your apps which you downloaded will "jiggle" and there will be an black circle with an X in it, click that X to DELETE that app and a dialog will pop up and say: "Do you really want to delete this app?" If you want to: Click yes.
And that is how to speed up your iPod
Bonus) - is how to DELETE an App
Thank You,
Apple 5