Ditto what Prasad said. Also, the old masters of what's now commonly known as Spencerian often used different slant angles (usually less than 52 degrees, from what I've seen). They also used different proportions from by-the-book Spencerian, and their writing looks significantly different. I learned this while using the Spencerian theory book and copybooks. I'm glad I started with the Spencerian system because it gave me a way of dissecting letters, but after I'd completed the theory book and about half of the copybook exercises, I switched over to some more Zanerian methods. If you're just starting out, I'd recommend finding some writing that you like a lot, and then learning the system the writer used.