I really like mine (32 gb white 4s).  I switched from an old flip phone that I charged once every 3-4 days, and I charge my 4s every night when I sleep.  I don't think that is bad.  I am not on it all the time, but I do use it to check email, text, phone calls throughout the day, and I'll play some games if I have to wait for an appointment.  I usually have at least 20% battery life left at the end of the day.  I take it off the charger around 10am, and it goes back on between 2-2:30am, so that is a pretty decent battery life.  If it gets better, great, if it stays the same, it works for me.