Before the pre heaters I had a lot of un burned smoke fluid slimed on the plane and a very weak line of smoke.
With the pre heaters I had less mess on the plane, which means I could turn up the amount of oil I was injecting which gave me a thicker line of smoke.
When I switched from Super Dri to Aero Cumulus, I got an even thicker line of smoke, but the real draw to me with Aero Cumulus was the hang time, I'm getting over 2 minutes of hang time on a calm day.
I have yet to try the Aero Cumulus without the pre heaters, its on my to do list before summer is over.
It is definitely worth the $4 of brass and the afternoon I spent making them, and I think I can make them better!!