I also switched from the 4S to the S3. I have not experienced any bugs or any problems with my S3. The only thing I miss is Safari and low light camera quality. I have read the S3 actually has the same optics as the 4S but there maybe be a little more software updating to do. If you have been on Android for a long time I think you will enjoy iOS and the 5. It is a fantastic phone. Many who are switching do not deny how awesome iPhone's are but many, like myself, do get tired of the same thing for the last 5 years.
If you want a change go for it. Be prepared to jailbreak it though. I would have never stayed with the iPhone if I could not have jailbroken it and added the functionality I desired, which Apple and the carriers restrict.
If you want a change go for it. Be prepared to jailbreak it though. I would have never stayed with the iPhone if I could not have jailbroken it and added the functionality I desired, which Apple and the carriers restrict.