Gridline or Pixel registration in earth relief grids?

I want to use the Global Earth Relief Grids. I see that for most of the resolutions available there are grid- and pixel registration. I read the cookbook about grid registration but I still don’t understand which registration I should choose. Pixel registration?

Thanks in advance.

Are you planning to combine the Global Earth Relief Grids with some other dataset? If you are, it will be easier if you choose the same grid registration as the other dataset. If you are not combining, then it makes little difference.