I run "with" my husband. I run about a minute faster per mile pace than he does. He keeps me slower on the long runs which is good for me because I have a tendency to go out too fast. At home on long runs, I circle back for him if I get too far ahead. We did W&D last year, and we did well together, probably because course congestion slowed me down (I dropped back to be in his corral) until about mile 6. Then I would "wait" (i.e., walk) at the water stations until he caught me up. We did that until we were on the path between HS and the Boardwalk, and I told him, I just have to go on, because it is hard to run at a pace that isn't yours. He ended up really not far behind me, maybe a two or three minutes? We wanted to run the whole race, but I think the rain bothered him more than it did him.
We had a good experience even though we were at a different pace. We hung together most of the way, but I got to finish on my stride, which was really cool. Then, because we stayed together, he was right there behind me. He was thrilled because I pushed him and he was ahead of his pace. On the other hand, I was about 9 minutes slower, but who cares? We had a great time together, mostly.