I agreed 100% when I first brought an iPad 2 and updated, it made it a paperweight. $600 IN THE TOLIET. Same thing to my iPhone 4, for 9 months it ran slow and buggy it was a nightmare, and I could not afford another phone.
I learn its apples way (form of marketing way) to get us to upgrade on the constant but these devices are very expensive and aren't worth the pain and loss, its the reason I will never buy an iPad again, the phone when purchase will not be upgraded to the next ios ever, i'll upgrade to the next ios when I buy a new phone. And to those that say "oh its ok it will work itself out" is FULL OF IT. try spending $950 on a device and have it slow down drastically when you NEED IT FOR RELIABILTY
Quit defending apple when it comes to software updates because its basically throwing your phone in a pool.