Given your circumstances, I think you've made the correct pick if you want a DL card.

If you cared about MQMs, the Plat or Reserve cards would be something to think about, but since you don't, there's no point in paying the extra fees to get them. Similarly, the DL Reserve card would get you SkyClub access, but as you don't fly a lot, you'd probably be better off buying a pass than paying for the Reserve card (if you even care about lounge access, that is).