I'm quite happy with the semi-lactic blue that I made. And the PC version, with a shift to a colder environment after the mould develops, should prevent the slip skin. Mind you, the inner paste was very tasty, and the runny bit had a wonderful mushroomy overtone to it that was very nice. Still, I think with proper temperature controls (i.e. lower) I could prevent the slip skin. I know these are larger cheeses, about 7 cm across and 6 cm tall (just measured it now, so that's the "well aged size"; this is the blue I've measured as the PC one is long gone). After all this talking about it I decided to have another taste and it's still very creamy and very nice flavoured. Not over powering, and no bitterness at all. In general, I would probably follow this make procedure again with few changes. I've not included any CaCl2. I've also only pierced vertically, but one could stick in on the side to increase the viening. I did generously salt the outside after removing from the mold, so I wonder if that slowed down the blue developement sufficiently to prevent bitterness? If it's not the mat that giving Tomer1 the problems, the only difference I can think of is either the strain of mould we're using or the form factor.
I'm planning on making another one or two over the holidays. Will see if they turn out as well again.