I have two De Buyer carbon steel pans that are the workhorses in my kitchen. I use mine for everything from eggs to meat. About the only thing I don't fry in them is fish.
The first one I seasoned in the oven using the method you describe. The last one I bought I just seasoned on the stove top with flax seed oil. A couple of light coats is all it takes before using it for the first time. Compared to cast iron, I find these pans very easy to season, but the one caveat is that you have scour off every last little bit of the lacquer coating that comes on the pan before you season it the first time. It's very labor intensive, but you only have to do it once. I'm wondering if this might be why some of your seasoning flaked off. I haven't had that problem with mine, so I can't say for certain.
The other thing I would add is that how you use and clean these pans is very important. I never use any soap or scrubbing utensils on mine. Make sure you preheat the pan for a good two or three minutes over medium heat before adding your oil and food. But I don't recommend using super high heat. Medium high at most. Even when searing meats, it really isn't necessary because the pan gets very hot. Too high of heat will only result in things sometimes sticking a little because the food overcooks before it has a chance to properly release from the pan.
If I'm cooking eggs, I can usually just get away with wiping these pans down with nothing but a paper towel and putting it away. If something does stick, I simply heat the pan for a couple of minutes over high heat, then pour some water into the hot pan while it's still over the burner to deglaze it. The water should almost immediately come to a boil. I'll then take a paper towel, fold it up into a little wad and, carefully, using a pair of tongs, wipe it around in the simmering water to clean the bottom of the pan. Anything stuck should come right off using this method. Dump it out, dry it out, and put it away.
While it's still new you might choose to rub a little tiny squirt of oil onto the surface of the still hot pan with a paper towel before putting it away. It will make things easier for the next time you use it. Over time, once you have a good layer of seasoning built up, you won't have to even need to do that much.
