One who is not familiar with iOS, it is a very fast OS. I have been using samsung S3 from the last 4 years and I can truly say you can safely bet on iPhone 5s. Zero hardware and software issue. Battery goes beyond 24 hour during normal usage.
By normal usage I meant 0-100% charge usage on iphone 5s after a 100% charge:
2.6 hours Phone
40 minutes Facebook
40 mins Whatsapp
42 mins Music in bacjground(screen off)
and total of around 30mins with other smaller apps
Although the battery is 1560mah, which is way lower than most smartphone, it the iOS that determines how efficiently the phone consumes the battery. I have never used iphone before, but what really surprises me is that once the phone is on standby when I go to sleep after 8-9 hours the is ZERO drop or maximum 1% drop in battery charge, which is pretty awesome. Ask any android phone user, you will have your answer.