I have an HP 48GX that has been kicking for more than twenty years and an HP 11 that is more than 25 years old and still flawless.  I have had this 12C for about 18 months and the number 5 key is already giving me trouble (have to press hard for it to register).  No drops, no abuse.  The overall feel of this new HP is cheaper plastic.  The keys feel hollow and light.  The available functions are great.  This is a classic calculator.  But the functions are no good if the keys stop working...