I attended a conference about three years ago and there was an agent panel. It included Jenny Bent, Janet Reid and Alex Glass.
Don't recall how this question came up but one of them answered (and I think it was Jenny) that she'll request almost everything that's pitched at a conference, i.e. that it'd have to sound pretty bad before she would not request.
But the interesting part (in a good way) to me was the rationale: the thinking was that if a writer has ponied up cash and taken the time to attend a conference, then it shows sufficient seriousness about their craft that even a bungled pitch shouldn't be reason not to at least look at the material.
Proof positive: I bungled my pitch (never done one before, blah blah) and Jenny still requested the MS. Few weeks later I got a polite rejection.
So being able to send off your materials as "requested" at a conference is, according to what we were told, at least a leg up from the regular slush. How can that be a bad thing?