My vote would be .44 special all day long. There was a reason it was Elmer Keith's favorite. It is a proven cartridge on game and offers a lot of flexibility for different applications.
Several choices of 200+ grain bullets getting near 1,000 fps depending on powders and bullet weight. Knockdown power and meplat vs. .38 special +p is hard to even argue let alone compare.
It just comes down to your capacity question. It isn't a lot different than asking someone if they would rather have 9 rounds of .380 vs 7 rounds of .45 acp. Is this for carry, home defense or just for fun? I am curious about that but it is hard to argue with a bigger hole and a heavier round if your intent is to stop someone with your first shot. They learned that lesson the hard way with the moros in the Phillipines.