PT, I didn't think you were that dense. Of course there is difference in filters. Basically all comes down to the filtration level. Gravity fed system requires a looser micron level. Although I do use 25 micro filters on gravity fed riders without problem though they recommend 70 micron for these systems.
But in general you should use a smallest micron that works.
Now I didn't watch snaggle tooth's video but so I do not he mention it but you should never turn one around once it has been used.