it was a difficult choice between this and the ti-nspire cx cas. i ultimately went with the HP because i really dont like the menu based interface on the TI. the HP feels more like a calculator and i was able to much more easily do basic everyday calculations on it. and thanks to the easy to use help system, i was much more quickly able to figure out more advanced functions as well. The cas system works well for both, but im not sure if the TI has Laplace and Fourier transforms. however, the HP doesnt have good 3D graphing either (despite what appeared to be a promising 3d graphing app online) while the ti does. it also took me a while to figure out how to properly create and use custom functions. once i had it figured out, however, ive found custom functions to be incredibly useful and easy to set up on the HP once you know how. i would also appreciate a bit more info on defining custom user keys, as the system doesnt appear to be as extensive as i'd hoped. so far ive only been able to define custom user functions onto number keys. I also havent delved much into programming this thing, but it does look like it may have more potential in that field, especially since ti started locking theirs down. however, available software is limited and ive found that downloading and installing other users programs is a far more complicated and buggy process than i would have liked. if not for TI's crackdown on their own programming capabilities, i would say they have the better system, but since i plan on learning to program this thing myself anyway, i decided to go with HP. The HP also seems to provide clearer answers in terms of roots or pi more often, and is easier to switch between numeric and symbolic representation with these answers. however, the ti was more intuitive when it came to using complex(imaginary) number conversions in exponential or trigonometric forms (still possible on hp, just less intuitive), and neither calculator performed well when taking limits at infinity. my recommendation would be to thoroughly test both out using the emulators (30 day trial for the TI) before making a decision. also keep in mind that as nice as the mouse is on the ti emulator, the touchpad on the actual unit is absolute garbage, while the touchscreen on the hp is actually pretty nice. that said, probably one of the bigger deciding factors for me was the emulator itself. i really like the emulator for the HP a lot more than the ti. and its very easy to do work on the emulator, or take notes, or design a program or function or user key definition, on the emulator, and then transfer it to the actual unit. i actually decided to get the HP when i decided that i would be using the HP emulator a lot more than i would the ti. even though the HP emulator was free, i wanted a handheld unit for exams that would sync with it and that would allow me to use the same interface in both environments. either way, both calculators are way overpriced and unless you need it for exams in college, i wouldnt get either. ultimately, i still think its a great calculator, but its not a clear winner over the ti.