I loved my TI-84+ SE and wish I still had it (had all sorts of custom programs on it but it got lost or stolen before I finished high school).

That said, I find it really hard to believe that they can't provide better specs and feature set for the cost. User-available memory of 3.5MB is incredibly low, especially with Python support. These could be really cool handheld computers if TI put more effort into their devices that already have a massive install base.

Currently, most of their popularity in my experience is "lock in" effect from teachers who are familiar with TI calculators and lab / curriculum materials that are specifically built around teaching through TI calculators. At this rate they're charging a lot and resting on their near monopoly status in education, which I'm sure is very profitable for TI.

There used to be a great app called WabbitEmu that emulated these devices on Android. I think they got a cease and desist but it was pretty neat to have back in the day