I have always been iphone user. I had iphone 3 and then iphone 4S. I was quite happy with my iphone 4S, till I downloaded ios 8. After that my battery life decreased so much that I had to charge the phone continuously. If cellular data was on, the battery did not even last 1 hour. At 50% the phone would shut down. By end, the phone had started giving me troubles. But I remain Apple loyalist. I was waiting for iphone 6 and bought it the day it was launched in India.
Review for iphone 6
It is much slimmer, lighter and bigger. It comes in 3 colors. Gold and silver colors are new and popular colors. The home screen button is now on the side. The font size is bigger and better. The best part is the battery life. The battery lasts me 2 days. Now I do not have to constantly charge it, carry a travel charger in my bag, nor charge it in car. I am loving it. The picture clarity is much better. Of course, you cannot compare it to DSLR's or even point and shoots.
I have never used any other phone- Android etc. Hence, I cannot compare it to others. Other phones are beyond my comprehension.
I certainly recommend buying iphone 6.