Topside is a very good mod. TC works "OK" but needs to be in TCR and adjusted for the best TC vape. I get a little bit of juice under my RDAs on top of the 510 connection. There is aseal of some sort just around the 510 connection that the juice has weeped into and I can't remove it to clean. We shall see if this will lead to juice entering the mod. Other than that this little guy rocks! No problems with power or battery life when using a 40T battery. Love the easy top filling! Eciggity rocks as always with super fast shipping and good prices.