The Pixpro AZ421 has a CCD sensor type which is better than most digital cameras of this spec and age. Most cameras that have been around for a comparable time to it have a MOS sensor type. CCD sensors produce high quality, low-noise images but consume a lot more power than CMOS sensors. CCD is the most common image sensor type used in digital cameras.
This camera's sensor type (CCD) is actually the best sensor type across all digital cameras of a similar age and type to the Pixpro AZ421.
The worst sensor type across comparable types of camera is MOS.
There are a number of alternative digital cameras that have a CCD sensor currently available which you might also want to look at including the Canon SX50 HS[plb_1410250_price], or the Sony DSC-HX200[plb_1475281_price] which has better reviews.