Thing is ... I have yet to try a top-fill tank that doesn't leak at all. One thing I like about my eGo One tank is it's totally non drip. Rebuildable AND nonleaky? Yes! I can easily live with bottom-fill, which turns out to be faster and easier than all my "take off the drip tip, close the air control and/or juice control, fill from the top, but be sure to leave an air pocket, then screw on the top, but just a little, then turn it upside down and finish screwing on the top, then open the air flow, then turn it right side up and put on the drip tip and ... oh, hey, it's still leaking anyway! Awesome!" top fill tanks*.
Of course my sample size is limited, and I'm sure(?) that there are non-leaky top-fill tanks, and maybe even non-leaky top fill tanks that you can just, like, open the top
and fill -- without all the voodoo shenanigans but I've just been feeling like bottom fill is a lot more reliable that way.
*
My KFM 3s are actually mostly good in this regard if wicked right, yet even they do tend to occasionally just randomly leak from the air holes for no particular reason. I try to think of it as an outpouring of love.