Given that it's a lead gen page, you could get some solid split-test data off $100 or so of spend on the advertising platform of your choice. However, I don't know if that's something you could afford. If it is, I'd definitely recommend it, but I can certainly see why you'd be inclined to trust the experts.

FWIW, looking over the "after" page myself, I'd agree that it's a much more solid longish-form sales page. You'll probably be fine using that as your baseline!