The batter looked great as it sat in the cupcakes cases, however I was worried that there wasn't going to be enough of it to make the 12 cupcakes that it claimed to make. Despite having to be a tad economical, there was enough for 12 healthy sized cupcakes in the end!
The marble in these cakes looked great when you bit into them. They also tasted fantastic, next time though, I'll put more vanilla and chocolate in their respective batters.
I also used my Wilton 1M for the first time when decorating these cupcakes and I have no idea where it has been all of my life! As you all suggested, a larger nozzle really has defined my buttercream swirls and I'm looking forward to using my 2D.