I was introduced to the 83 Plus and it was simply the most mindblowing device at the time. We were given a sheet to share with our parents on why it was an important device to own/borrow. Me and several friends would trade apps through the TI-Link cable, and we would play games, write software for it and there was even a popularity rank in school about whose program was installed on more calculators.
For a lot of people it introduced them to TI-Basic which was quite capable, and for others you could get into Assembly which allowed for more powerful applications. There were 2 parts of the memory, BASIC programs were in regular memory that could be easily erased, and another part which was Flash Apps.
I later upgraded to the 89 which had a better CPU, screen resolution and processing power and it was phenomenal in helping me understand every single math class, including EE/EECS. It made me sad to see them banned in exams, because having a 83+/89/any calculator was in no way helpful in any of the exams I took, but it was more of a "control the students" thing in college. The Math department determined that because they couldn't prove that people were not using the internet/portable PC's in their calculators, that they could not guarantee the fairness of it all.
Weird argument to make knowing that a 20 year old student was engineering a full internet capable PC into a calculator at the time would have been the envy of the world (and every engineering program).
This all depends on the quality of education and not simply handing out problems that require rote memorization of the methods to solve an equation and instead derive or figure out the equation yourself after understanding the problem after which you're free to use the calculator to "plug and chug".