Those systems are both hardware and software upgrades, so you may as well spring for the 360 parking and nav. No regrets later on after you've owned the XS for a while. But I'm one to purchse cars and not lease, so they generally stick with me for a while.
In that case, it's better to have a fully loaded infotainment system than regret it later.
I also think that come time for these to show up on dealer lots as pre-builds odds are they will come fully loaded, easier to sell them at that point compared to a base trim, especially given how much people want all the latest tech these days.