I saw these in Tesco today and bought one. It's quite small bar that looks like two rows of flat Maltesers fused together. Inside there are small bits of Malteser in solid chocolate.
It was 57p (a lot for a bar that size, I think) and I thought it was too sweet. It's the amount of chocolate that makes it so sweet, I think, because I think it's cheaper chocolate than that on regular Maltesers.
I know I've always said I'd like a Malteser Bar, but what I meant was a Topic-sized bar, with quite thin chocolate and a huge chunk of solid malty bit - like a Crunchie.