Bitmap Sheets - tiled or single row - which is better?

For alot of my animated sprites, I wrote a little program to read in all the bitmap data, crop the images and output a single sprite sheet of all the bitmaps, plus the "array" data needed to find and copy out the specified frame.

This has proven to save both memory and preformance when dealing with large numbers of frames

However, when I look at several example of how other people do sprites sheets, their final sheet is always tiled

So if I have an animated sequence of 60 frames, (assuming that each source bitmap is, 50x100 and there is no cropping to be done) I would end up with something like this:

Bitmap: Size = 3000x100;
TopLeftCornerArray = [[0,0],[50,0],[100,0]...[2950,100]];

Is there any difference between doing that, instead of creating a sheet bitmap, that was say 10 frames per row over 6 rows giving me a bitmap that was 500,600?

I mean, both bitmaps are made up of 300,000 pixels regardless...

I was just wondering if there was a good reason for not putting them all on a single line.