I have this same kit and completely gutted and remodeled my entire downstairs with them. Mine came in a hard plastic case that protected them even when said house burned down, much to my surprise (helped that it was sandwiched between a metal toolbox and drywall downstairs, but did take some digging to get to).
I’ve never had a problem with the nicad batteries. They always held a change nicely even over time. With the lithium batteries, I hear when they die, it’s instantly, as opposed to the relatively quick, but still noticeable voltage drop with the nicads. Basically, you won’t get surprised and get your drill stuck in the wall with these. I don’t think I’d ever pay the extra money for lithium drill batteries.
Also, I used the drill significantly more than the driver, even when I was driving a pile of screws into the floor (strongly reccomend torx over square or Phillips). The driver spins so damn quick, and with the impacts, it’s much harder to feel and stop at the right time and not blow through the material. If you’re going into something much harder, like building a pressure treated deck, the impact driver probably would reduce wrist fatigue a fair bit.