I don’t own any heritage cast iron, I have a bunch of lodge ironware. I primarily bought a pan for camping trips as it felt a little more authentic. Since then they’ve found their way into the kitchen and I’ve added and use at least one daily.
A couple of years ago I was given a de Buyer carbon steel ‘wok’. It’s a beast and I’ve included a picture of it next to a standard 12 inch lodge pan.
You treat de Buyer carbon steel in exactly the same way as cast iron - seasoning and cleaning. Paul talks about the old cast iron having a milled surface and lodge is pitted. Carbon steel is dead flat.
I know the lodge is slightly bigger, but that’s a huge difference. I’m likely to fail my ‘fry an egg on cast iron’ badge because I can pick the thing up to slide an egg around, I had to use a metal spatular.
Anyway, this isn’t an advert for de Buyer as I’m sure there are other makers out there using carbon steel. I do really like there pans though and think they could be a good alternative to cast iron. (They also ship them covered in beeswax, which is nice).