Anyone grown Fatalii chillies?

I'm trying them this year for the first time. I sowed them in January, they germinated fine and I pricked them out on 20th Feb into 3" pots. And they've barely grown since then. They look healthy enough but they're no more than about 1" high, whereas the SuperChill that were sown and pricked out at the same time are now about 8" high. Do they always grow this slowly? If so, how on earth do they grow enough in a season to ever produce any fruit?