TI-36X Pro—Replace the batteries or just get a new one?

[lrdheat]

The TI-30X Pro MatHPrint is a nice upgrade from the 36X Pro. Same function set, but much faster than the 36X Pro, nearly as fast as the CASIO 991EX. Nice to have history remain intact when turning calculator off and on, or changing from one application to another. Can still use solve with d/dx and integrals. Like having product in addition to summation. Like how, as on the 36X Pro, an integral can be executed with max(function 1, function 2). Appears as if regression had an additional choice added.