I've used the cold oil method last few times we've made french fries, your chips. They have come out really good as long as you follow the technique, recipe exactly. It's actually pretty easy in that you put them in the cold oil, turn on the heat, and then just leave them alone. You just have to follow the prep, amount, time, patience, and leave them alone rules, the last of which seems to be impossible for some people. The only bad thing about them is that the technique makes a limited quantity unless you run 2 or more pots at the same time.
As far as what we call chips, which are potatoes sliced extremely thin on a mandolin, then deep fried very quickly, I cut them as thinly as possible, soak them in hot salted water for 1/2 hour at least, rinse under tap water, drain in a colander for a few, then spread out on paper towels to get fairly dry. I don't know the exact temp I fry them at, it's a setting in my stove I use as I don't like getting the thermometer or the deep fryer out. It's a 7 out of 10. I fry them until light golden brown, which takes hardly any time since they are so thin. Remove from oan with a spider or slotted spoon to a rack, sprinkle with salt. You can keep warm in the oven, which you may have to keep them in even if it's not warm. These have a tendency to disappear almost as soon as they are out of the hot oil if they are left visible and accessible. There have been instances of hand slapping to keep them from all being eaten before dinner!