I don't have experience with the S4. I had iOS though from 2008 to early this year and then switched to Google's Nexus devices. Here is the my scoop from someone who had iOS for a long time. Stock android at least is nearly as stable as iOS. I say nearly because there are bugs every now and then. For example, the first month that I had my Nexus 10 tablet, it would restart on me every few hours of use. The 4.2.2 android update corrected the problem, and I didn't have the issue for long, but for someone that purchased the tablet at release, they would have had the glitch for several months. That's been the only glitch so far on the N10, and doing web searches, it was fairly wide spread. For my nexus 4, I hadn't had any glitches until the new Google play a couple weeks ago. Nearly every time I unlock my phone now, Google play music is on the screen, even when it wasn't the last used app. It's getting super annoying. Other than those two issues, the only negative I can think of is that there's more ads while browsing. Sometimes it's super annoying. It will be a rolling screen on the bottom and a side screen on the left, and no matter how many times I click the"x" it always comes back getting in the way. With all that said however, Android is so much superior to ios. There's many more features and I find that the entire OS is more logical and easier to use. You might have a learning curve, but as long as you go in with an open mind, it's easy to overcome. Another issue is that web commenting isn't as good. The text boxes for commenting usually suck. Take this comment for example, the reply box is small and can't be made bigger. I can see three rows of text. That is a common theme with blog commenting for me. The only specific I can say regarding Samsung, is that during my approximately year long investigation of Android (which included a crap load of web research and also just playing around with phones in stores) the s3 was always glitchy every time I played with it. For example, once I went to a Verizon store and played with the s3 for about a half hour. It would reset on me and close apps sporadically. It did this 3 times in a half hour. I did play with the Note 2 on several occasions and didn't notice the same glitches. This was also on an older version of android, which was less stable. I decided to go with stock android because I wanted fast updates directly from Google (for example Nexus 4 has had 4.2.2 for several months already.) Here is my bottom line advice for you. Go to the stores and play with the s4. If you like it, make the switch. Get familiar with android and how it works, and I'd be willing to bet that you'll love it. I will never go back to iOS.