The verdict
If your question is where visitors or users get stuck, pick Heap. If it is how satisfied customers are, what staff think or what a market wants, pick SurveyMonkey. A small B2B team that can only start with one should pick the gap it has today. With no behaviour data at all, start with Heap. With traffic data but no feedback, run a survey. Do not use a survey to guess at behaviour, and do not read satisfaction from click data. They work well together later: use Heap to find where people drop off, then send those users a short survey to ask why.