I have been hand quilting a quilt on an off for months. Some days my stitches are better than others. I'm not planning on entering my quilt in a competition so I don't really care if it's perfect, it's just fun to do. I'd say I average around 7 stitches an inch. Part of that is because I mistakenly chose batiks (with a tighter weave) and I am not using wool as a batting (which I've been told is like quilting through butter). I used 80/20.
I recently saw a vintage quilt and it was just astonishing with 12 stitches per inch (I got a ruler and measured because it was so unbelievable). It was a huge quilt and absolutely perfect. So it can be done --- but not by me! :P Good luck to you if you have the patience!