<< It is a novelty if you can get any help with them [HP] from a Math department... >>
That might be true in a math department, but at my college, HP is the platform of choice for engineering students. If you can learn a complicated PC and even know how to build them, I'm sure you can also learn how to use an HP. Right now, I use a HP 49G (the newest model). The only gripe I have about it is that it has an AWFUL printed manual that doesn't even go over a fourth of the calculator's capabilities.
If you're a high school or early college student, then I would agree, stick with TI. They are more user-friendly and it is the standard in math classrooms. For engineering and such, you might want to look at HP. I personally prefer their calculators, but that's just me.