In the old days, when comparing 426 hemi to 440 wedge, the hemi was always quicker. Then you look at all the heavy cars in the 9's, and it was always them hemi's. The wedge engines were the ones in the 10's.
Now with the advent of all the R&D, both have got better, and both are capable of 8's in a nearly street weight car at 572 cubes, which is better...Does it matter at that level? I like both, and for me it would depend on the application and what I want to do with the car.
For my car, there was no other choice. I had a tunnel rammed 440 in the car, and nobody even noticed it. I put the hemi in it, and it became the crowd favorite. Other than the heads and pistons, they are pretty similar engines. Which is better, again depends on the car and the goal in mind I think.