I have just started algebra 2 and with the +CE being the newest calculator from TI, my teacher suggests that we should get that one. But, she does also say that the Nspire CX CAS is better and easier to use (?) and if we can we should get that one. I have currently ordered a Red +CE and am awaiting its shipment. The main reason I did not get the CX CAS was because of the fact that I am looking for a long term calc, and it is not allowed on some tests.

Thanks.

Okay, I own both of these calcs so I think I'm qualified to answer this question let's begin by looking at both options, then my opinion will follow:
ti-nspire CX CAS is indeed superior when it comes to calculations, because it has a CAS. This means it can perform more advanced calculations such as derivatives, integrals, limits, expanding polynomials and simplifying equations, which the ti-84 plus CE can't do. This being said, you teacher is dead wrong about the Nspire being easier to use, it has one of the highest learning curves of any ti calc, while the big ti-8x series are known for being very intuitive. The reason the ti-nspire CX CAS is not allowed on a lot of tests is because of it's ability to perform algebraic manipulations which if you know how to use it, would essentialy solve the exam for you. As for performance, the ti-Nspire is superior, although both technologies are insanely outdated (they are calculators after all) the Nspire has a much faster ARM processor while the 84 has an EZ80. As for memory, the nspire has a lot more of it like 100Mb instead of 3mb. For programming, the Nspire can be programmed in nspire Basic, Lua and C/ASM, while the ti-84 plus CE can be programmed in ti-basic and C/ASM.

Now for a bit of opinion: I think you are much better off with the ti-84 plus CE even though the Nspire is technically superior. First of all, the 84 is much more popular than the nspire, this means that there are countless references and people you can ask for help if you have any questions. The less popular Nspire has little to no doccumentation, the pool of people who can help is much smaller and this is worened by the fact that it is a much more complicated tool to use. As for the performance boost, you really don't need it unless you will be programming very intricate things because the ti-84 plus CE's EZ80 can handle pretty heavy programs very well. Also, it is accepted in more exams which is nice if you intend to use it during your exams The nspire seems to be mostly designed for people who work with numbers for a living rather than a calculator for students. It is kind of meant to be as good as it can be while the 84 seems to remain a little limited because ti wants it to always be accepted in exams to keep their student buyers.
tl;dr, I think you did good

Thanks

At my school, every classroom has class sets of TI-nspire CX's (not CAS, for the reasons listed above), so I have had some experience with them, despite my preference to my TI-84 Plus CE. When I am using the Nspire, I notice many more preformance, display, and graphic glitches than I have ever seen on any of the 84's. The WiFi connectivity seems to have issues every once and a while, and worst of all, when it isnt working, the calculators error message system is much worse than the 84's (of course, I know what most of the 84's errors mean while many do not). They are probably fixing this in OS updates, but I have witnesses about 5x the amount of graphical display glitches on the Nspire than the CE, so if you want a cleaner look, go with the CE. The CE also has a much simpler user interface, with one main home screen and calculation pad, with most other features just a keypress (or two) away. The touchpad on the Nspire may seem promising, but it seems too unpredictable and unresponsive to be useful, and I find it is more of a nuisance than a benefit, as the mouse will pop up and decrease my productivity when I am trying to stick to only the arrow keys. As mr womp womp said, the Nspire is more powerful, but only once in my PreCalc class last year did we do something on the Nspires that the 84's couldnt do, and it was only a shortcut that would be used for only checking your work (because #youvegottashowyourwork).

Anyway, Ive hoped ive provided some additional information to your decision.

NOTE: I may be slightly biased to towards the 84 models because I love them and the Nspire's are different so HATE but I still see the power in them.