I tend to use the Phoenix RBA Dripper. It is a simple setup which works for me. I still have the factory setup in the RBA which is around 1.7-2.0 ohms. I set it at a good wattage setting and just let it go. But, to me I still like to drip and having a RBA makes it better for me since I can adjust to my liking when I will eventually rebuild. I am thinking about having a goal of 2.6-3.0 ohms. That way, I can rock it at a higher setting without worrying about blowing an atty. But, my other devices usually have either a Kanger ProTank or ViVi Nova on them which are also quite nice to vape with. I think whatever is best for you is the best topper for a device in my honest opinion. You cannot go wrong with anything even something as simple as a clearo.
Good luck with whatever you try, just find which works best for you because that is all that really matters to be honest.
Keep trying until you are sure that your setup is giving you the best vape ever!