Capturing HTTP requests is fine if all you're concerned about is the processing on the server side. It makes sure that the requests are processed properly and proper responses are received. It's simple, streamlined, and very low level.
Meanwhile, page exercise is good to test the specifics of the application, the user interface side, and how the manipultation of that UI impacts the requests sent and received.
In my opinion, HTTP request recording is great for performance testing and unit testing, but Page level scripting is best for full functional testing.
Automated Testing Evangelists
Definition expert - noun - Unknown drip under pressure
I tend to agree with Robert. You really can't beat page level testing for the majority of your functionality. I think there is a very niche area to which capturing HTTP posts will apply (at least in my experience). It has it's use, but I think the page level stuff is mucho more importantado.
9 out of 10 people I prove wrong agree that I'm right. The other person is my wife.