I already have a Texas Instruments BA-35 Financial calculator that I purchased back in 1993. It has served me well. A few weeks ago I misplaced it. After two days of searching, I gave up, and purchased this BAIIplus to replace it.  Luckily, I found the BA-35 a day later.  When this new calculator arrived, I was really disappointed in it. First, it FEELS CHEAP...second, it is HUGE and CLUNKY and has a very awkward hard shell that you must REMOVE then snap onto the BACK. It took several tries to get the calculations sequence figured out...there are some minor changes from the previous calculator.  I will use this as a backup, but it is too large and I hate that pop-off cover.(the old one is slim, and came with a nice flip-open vinyl case, with an interior pocket where I keep the instructions, should I need them.)