I have a nSpire CAS. While those features are really, really good, it does have a significant flaw compared to older graphic calculators (including the TI-89, which is probably more of a predecessor to the nSpire CAS than the 84 is as the 89 also has CAS): actual boot up time.

The 84 and 89 are instant on while the nSpire has significant boot time. I guess you are suppose to leave it on but let it “sleep” like a modern smartphone, but the battery life is bad even when the screen is off. I’m not sure how the 84 CE compares, if it’s “just” and 84 with color or it’s something much more modern locked to running an 84 emulator.