More and more, I'm seeing the value of calling the eConnect stored procedures directly. There's a lot of overhead in spooling up the .NET code.
I only do this in lower risk areas... I probably would not normally do a SOP Document because you have to handle so many errors and be sure to back out any lines that you create if there is an error.
But a SOP Void is easy and painless. I had to do this today for a client, so here it is for your enjoyment.
Cheers.