I think the difference is in the details, but the details matter. I would really be interested to get some experience from people who actually had projects in both languages. Because then you get to know about differences that actually matter.
A tiny feature of the Nim language, the dot call syntax for simple procedures in combination with the generics really changed a lot of how I structure my code. My mind is now free of class hierarchies mixins traits and all that other crap I simply don't need anymore. Maybe here and there, but I don't want it anymore, and I don't try to use it anymore to solve my problems. I did not expect this to be so nice to work with. D is more with the old fashioned class systems, at least that is what I expect it to be. I did not actually use D, I just read the documentation and presentations about it.
