As an engineer, I've used nothing but hp calculators due to their obvious superiority. When I used my hp48gx to it's grave, and a lot of use/abuse it took, I bought the newest and "best" hp on the market... I was sorely mistaken. This calculator has poor key response and is prone to malfunction. The reliability of my calculator is key to me, and I plan on returning this one and getting a used 48gx. Hopefully the next generation hp calculator will return to past quality.