I just got one done for my stepmom of her horse for mothers day and it turned out really well! Also, I didn't know this ahead of time, but if you bring in a picture for them to use for the silhouette instead of sitting down for it they'll stop to take the customers who do need to sit down for theirs. Which makes sense of course, it's easy for us to wander off and do other things (like shop or get fast passes...or both in our case), but when you're waiting to sit down for your silhouette you can't really go anywhere.
We're going to get at least one more horse one for my dad for his fathers day present, but I don't know if I can bring myself to get any of my pets done... There's just too many to figure out where to start.
They really are amazing though, considering I can barely cut a straight line.