I have two different antennas here. One is the 5dBi version made by Jetvision, the other one (currently in use) is the Vinnant 7.5dBi
Both were operating for a week at my Airsquitter and the difference is almost zero. With a Vinnant you’re not doing something wrong, it’s about half the price of the Jetvision.
You can read my testing (without real test results here:
My suggestion: If starting new, the Vinnant are absolutely ok.