Hi Searing. The warmth difference you perceive most likely is one of two things. Bottom coils typically don't have as much warmth due to the fact that the coil is so much further from the mouth piece , hence the vapor cools on the trip from the coil to your mouth. Slightly, but it does. Second issue could be the ohm load. If you know what the ohm load of old top-coil clearomizer you where using, check to verify if this one matches that old number. You could possibly replace the coil portion of the t3 with a lower ohm load head and hopefully compensate for the difference, but that assumes that the head you have is a higher ohm load head. I didn't think that there was a huge difference when compared equally against Ω-Ω evenly, there was a difference (for me) but not a giant one. Happy Vaping.