Agreed. Authorize.net is problematic. Not really because of Authorize.net, but because you have to tie it to merchant services--and every one I've used with Authorize.net has been uniformly awful. Everything is targeted to businesses with card reading equipment, rather than online processing--all of the folks at the merchant services companies are baffled by questions about online stuff (and Authorize.net refer you to the merchant services people for a wide array of queries). It's just a poorly matched set of tools.

API support for Authorize.net is excellent, though...that's the only reason I use it. Some weekend I'm going to convert to Google Checkout or something else.