If you compare it to a AOSP rom you will find that its most definitely slower. You don't realize how much Touchwiz taxes the system until you compare them side by side. I took my Galaxy S3 to the Samsung store with a SlimRom AOSP Rom, compared it to the S4, everything on my phone worked smoother and faster! the apps opened quicker, camera worked quicker. The overall phone is just smoother, you have no monster ui taxing the system! now if your the type that needs all the gimmickry, then by all means this is a great phone, but you'll never know the true potential of the phone until you get rid of touchwiz! and using a launcher doesn't do that, all a launcher does is change the sesame street look of the phone. If you need a phone that you can swipe down the crack of your A#s and get your body temperature, then baby, touchwiz is your puppy!! But if you want a smooth operating phone that just works...then look for a google play edtion or put a custom rom on your phone, I have and have never looked back, it would be a snowing day in hot place before i could ever go back to touchwiz.