Just to expand a bit on the usefulness of the information, recall that not everyone flies from VOR to VOR or, lacking those, can follow an interstate, so here is a scenario which shows how to use the information a D2 might provide.
Let us suppose that you are flying your Briggs Bugbasher from Tucson to Yuma, across the Sonoran Desert. About halfway across, you lose all of your electrics, while up ahead of you is a decent looking Cb, which you intend to divert around.
By the time you have done so, you are going to be a bit uncertain of your position, particularly since there was another Cb behind the first one. You are lost and actually a bit shorter on gas than you would like to be.
However, you do know, because your D2 tells you, that you are at N32.07 W112.22.
You also know from your airport landing chart, that Yuma is at N32.39 W114.36
This might never have been important to know before, but it is a lifesaver now,
because you know Yuma is ahead and slightly to your right, exactly where can't be seen.
So you take a very definite turn, say at least 30 degrees to the right and fly until the D2 tells you that you are at N32.39. You then know that you must be East of Yuma
If you then fly due West, you can be sure that, in fairly short order, Yuma will turn up!
Now, in fact, flying from Tucson to Yuma is probably not that difficult, but for those of us who fly over the Pacific, perhaps from New Zealand to Norfolk Island,(a 3 mile by 2 mile island, 450 miles from the nearest other land) or perhaps over the Sahara to Timbuktu, Lat & Longs are really good things to know.
It remains the reason I still carry a sextant and tables and know how to use them.
Having a D2 which gives us that info would be a truly wondrous thing!