There are usually three type of links in directories
1) Featured (Almost 100% Paid On Every Directory, It usually has fastest approval rate but costs very high)
2) Regular (Paid on some directories, free on some. If paid, then chances are that webmaster will approve it fast. If free, then it might take few days, weeks or even months depending on how webmaster treats it).
3) Reciprocal (Free on Most directories, Many directory owners never approve free reciprocal links or once in every few months. It has the worst approval rate in my opinion).
Reciprocal directory submission is better for faster approval but is is two way link building process and due to this not much worthy. Therefore most of the seo experts and webmaster go for regular directory submission.
By studying articles, forums threads and reading materials written by experienced people who have tried out directory listings, you will notice it is better to stay away from reciprocal types of links, especially the ones coming from certain commercial directories.
Two way links were some years ago very powerful in terms of helping websites getting better ranks and higher PR scores but today, only one way links are considered to be truly powerful.