I am planning for a survey research project (national representative sample for 15 min survey) and am considering which panel/sampling company to use. I have used Dynata before, they are relatively cheaper ($3.5 per participant), but with my past experiences, not great data quality. I usually put attention check questions in my survey, and they will filter out a huge amount of participants. Even though they are not counted towards the total, I don't feel good about the quality of the data. So this time, I wanted to try Qualtrics panels. But they are a lot more expensive ($5 per participant), so I wanted to see if anyone has used Qualtrics panels before, and how's the data quality comparatively? Is the price worth the service? Thank you!