Everything you buy from China will have the tendency to leak. For example I bought a pack of Kanger T2s and one of them leaked, so 20% Failure rate. I've seen on youtube where good folks will have all five devices leak from a pack of five. That is just ridiculous. This is not going to stop until we all put our foot down and tell the manufacturers to make better quality products. There has been some discussion of this subject going on in some threads in different sub forum within this website.
And the funny thing is it only literally cost pennies to increase quality control to the point where we will only see a failure rate of less than 1%. But the nature of how manufacturing businesses are ran in China lend the situation to where we are today. That is if we have just one Clearomizer fail out of five then we don't really care - especially when you break down the cost of that Single piece and it ends up being $3 or less. As a Western society if it's that cheap then we tend not to care if something goes wrong. We thing, "Gee willakers that was only a few bucks, no wonder it failed - it's cheap anyways'. Well that thinking is very flawed. No matter what the cost is we need to hold the responsible parties responsible for their crap manufacturing. I would be more than happy to spend 50% more per unit if that means it will work right and not have issues from the get go.
Now to you question, you may want to look at some DCT
tanks and some more expensive rebuild-able jobs. Though no matter what you get there will be the potential for leaking. Especially if you are not careful with what you are doing.