The games aren't really comparable. However we can look at content..
Stations/bases: how many in ED ?, in NMS there are simply hundreds and probably soon, that number will shift into thousands of bases/stations (if it hasn't already), most all community made.
Planets: well we need not talk about the vast amount NMS have and the little ED has.. in comparison.
Ships/flight: Ed is better for ships and flight, but NMS have a nice choice of ships, that I feel, may become customisable in-game sooner rather than later and they won't be paid skins etc. But for space flight, I would go to other games anyway. I do however enjoy the point and push of most space game flight. But it doesn't fulfill much. ED & NMS are both point and push, just ED does it better. When it comes to feeling your ship, then really you have to move to other games for that.
Space: space is just not comparable, NMS is fantasy sci-fi, whereas ED tries to be realistic, well, near anyway. So it's a case of what type of space rocks your boat at the time. Both use skyboxes, so you can't win..
Space legs: enough said..[yesnod]
Character: NMS has a customisable character you can play with. ED... well..doesn't.
Scale: something I'm very curious about. In NMS we get a very good idea of scale. The player understands the planets are not full size in any way. But at least we get the scale feel on the planets we have in NMS, plus the bases, stations, caves, freighters, etc..
On the other hand in ED, I don't see that scale, it just looks odd in ED. Stations look false to me, the vehicles look like toys, so if you compare a ship docked, to one of those vehicles, well, it looks out and odd.
Planets are not full size in either game..

controversial:.. But 'I believe that'.. After using full size mod planets in Space Engineers. The planets in ED don't do it for me..
Water/underwater: enough said.
Landable planets: again, enough said.
Underground/caves/caverns etc: well, we see where this is going.
Atmophere & weather: ...........NMS...
Walking: ............NMS......
Building: ..........NMS.....
They are very different games and as said above, can't really be compared theme wise.. However content wise.. NMS wins hands down, for me, from the above quick assessment.
Now just to add...
Game-play.. How players feel for a game..
That is completely personal and will vary from player to player. It depends on what your looking for in a game.
Of course, if like me, you like space games.. Then play both and any other that rocks your boat. I do..
Edit: Hang on.. I forgot aliens, pirates plus terrible ai..
Well ED has aliens, we're yet to see, if they give them legs that is. Or maybe pic on card type of thing

Pirates, scourge of the universe.. Both games have pirates, either are fairly basic.
and that leads onto ai/npc's, both games have these, well ai at least. Both are basic ai really.
Creatures, which could be classed as alien of course.. Well.. NMS again, but they have basic routines. Plus the sentinels in NMS are fairly basic, just game fodder. But they are present.