As far as leakage is concerned, it's a problem with all Alkaline type batteries. It's not so much a matter of if, but when and I would assume that off-brand batteries are more likely to leak sooner, especially the really cheap variants.
It's a matter of charge; as an alkaline cell discharges, the negative electrode (the zinc can) gets thinner, until it eventually perforates. One more reason to pull out the batteries if you aren't going to use your gear for an extended period. A friend of mine lost her LS-10 due to this. The more the batteries are discharged, the less time you have before they leak.