ok I know of only one reason to remove the seeds that might make a difference for some people and that is if they have ever had dy-per-ti-cu-li-tous. I know this isn't spelled right but you pronounce it like it looks.
This is where the seeds get caught in the intestinal tract and form pul-ups. again I can't spell! These pulups would get infected to the point that they had to be surgically removed. My MIL had to have several operations done on her to remove these and they always told us that they were from the seeds in the tomatoes that didn't pass through her system. So if you have intestinal problems then I think the removal of the seeds are necessary.