Oh, and I forgot. I have a couple of these, that is cast iron bakestones (meini), one of which is probably over a hundred years old, rather pitted on the heating surface and would just never heat up on a glass-topped cooker.
That is, if you didn't break the glass putting it down :-)
I use them mainly (or did, before we lost the gas) for Welshcakes. this recipe is close to the one I use, though I tend to use sultanas or raisins instead of currants, half plain and half self-raising flour and avoid the baking powder which does make fluffy cakes but also leaves a dry taste in my mouth. Anyway, the slightly flatter, denser cakes are my favourite. Lard makes a difference - some recipes use only butter, but definitely avoid recipes using margarine or oil.