What wattage are you running it at? I run a .34 build in my goliath v2 and it's been perfect. Once i get over 60 watts the wicking can't keep up, but at 50 watts the thing has great flavor and good clouds. The goliath has plenty of air, not sure why you wouldn't be able to hang right around .2 - .3, but that said the .34 is the lowest I've built mine. I do prefer twisted coils over the standard ones. Your wicking looks pretty good, i run mine just slightly longer, where the tails are pretty much even with the notched out portion. It may be a little thick, might be worth trying just a little less cotton. As to the leaking, is the juice coming out the airholes? Are you top filling it possibly without closing off the juice feed?