I have a Toptank Mini and plan on buying another one. I like that you can buy coils or make your own. It's pretty versatile. No leaks at all so far. Top fill is nice, but I agree that it is a con that you have to refill it when you still have a quarter tank left like Drysprocket mentioned. The only other con I can think of is that it had a nasty taste to it at first even though I washed it before using it the first time. It took washing it 4 times with Dawn before it was usable, but after that, it was fine. I like to switch between sub ohm and higher resistances, so it would have been nice if they would have included a smaller drip tip. I tried several smaller drip tips (including Kanger ones) with it, but they wobbled around too much. Otherwise, it's been a great tank for me.