It is easy to use as it has drag & drop features for creating form templates which I love! Also they provide great customer support when there are issues (which aren't often).
Nothing so far but this was expected since its an online solution from them - nothing bad about that though at all :) Make sure your looking into how long their refund period will be before jumping in because after 14 days most people realize "this isn’t what i wanted". You can easily copy paste any template or page if someone makes changes/edits without paying extra money per revision of course..