Yup! And the TIN Mesh Creation in QGIS was the first way I played with to model the terrain too, though I was less happy with how it looked. It's useful for me to see where the data is too sparse, but not a great view of the land itself.

You're correct, my data is still too sparse in some areas to give a good set of contours. It's been fun to see how the contours change as I add more data to the survey. It's part of the reason I decided to buy my own gear, because then I can spend as much time collecting data as I want without more cost.