The short answer is: Almost all of them are harder to make than they look. The suits I've made from PVC gave me surprise by ruining my needles. The vinyl would scrape off onto the needle. It made for much slower sewing and a lot of needle replacements; the machine sewing is usually one of the easy steps. Also, I hate making accessories like gloves. You'd think it's just stitching pieces together like anything else, but they are so difficult and I have to hand sew them. I'm terrible at putting in zippers and elastic which are in almost every suit too. Trying to add fur to Black Cat was also a complete bitch of a process and I was never happy with it.