I can generally tell the comments I get from a phone and those who are on a keyboard. It isn't just the length of the comment itself, it is the brevity of thought and sentence structure. There is a different feel, which is of course a natural result of changing the writing tool, just like changing the medium and brush set for a painter.

I hear from many who say they are better on a phone, but I think it is going to be A long time before the great American novel is produced from a touch keypad on a 4inch screen.