This is a good calculator as would be expected from Texas Instruments, who have been in the calculator business for decades.  A calculator should do the functions that it is supposed to do, which this calculator does.  However, like several other's have noted, the keys can be a challenge.  I've had to start over after entering a number due to the numbers not enterring as they should have.  A good press of the keys takes care of that issue, but most calculators do not need to have the keys pressed firmly for the correct operation...  If Texas Instruments could redesign around the key issue, this would be a five star calculator, as the case and display are well designed. I have only used this calculator for a total of maybe 15 - 20 hours, and the keys may work better over time, but I have not seen any change during the timeframe noted.