Yep. And I'm sure there are good reasons for using both methods. The thing is, no two clients are going to want the same thing. Where I'm getting so confused, is all the options in both the Checkout Wizard and the Insert Checkout form only mention PP Website Payment Standard or Pro. But most all of the documentation talks only about PP Express Checkout.
So as I am following the gsg I am getting confused.
It seems that most at WA are pushing the use of PP Express Checkout. And I'm sure it's for a good reason. My prediction is I will soon see that, but as it is now, this is my first use of eCart for a client and they want Standard. I'm going to try to eventually setup a demo cart using both methods. That way, they can see both in action.
Honestly, I've setup lots of simple static "Buy Now" and "Add To Cart" pages for clients. But nothing this interactive. PayPal is difficult to integrate due to their limited options. And eCart appears to have this extra control. So I really want to learn both methods so I can use it for extreme shopping carts and the simple 5 product page or subscription.