I got to “play” with the PayPal SOAP API last week for a website I was building on.  It was very easy to work with and I was surprised at how quick I could could get a checkout page going in ASP.NET/C#.  It could have been quicker but some of the documentation on the PayPal site was either out dated or confusing.  Luckily with a quick Google search I could find the correct way to create the main SOAP object.  If anyone needs an example of how to do a Direct one time payment let me know.