I tried doing a leaf using this stitch on Aida and just couldn't get it right. I didn't have any problems on the plain fabric where I roughly drew a leaf shape. You can see here where I cut my losses and moved on.
I actually like this stitch although from reading some others' comments, it doesn't seem to be very popular. Leave it to me! I didn't have a problem with it until I tried stitching it along one of the seams on my CQ block. But check my blog. I have a photo of some leaves I did using the Cretan stitch. I liked the results. I found it easier to do something like that on plain fabric rather than the Aida for some reason. Moving right along to week five!