Nope, Penguins are utter dog's balls compared to Tim Tams. Night Fury says it's just that "Tim Tams are crunchier than Penguins" but I would instead say that a Penguin is more like the creepy, unwashed brother that Tim Tams don't associate with.
Anyway, yeah, I've been in the UK for too long and have very strong feelings on this issue...
Yes, I agree! I remember my friend bought penguins to try because some heathen said they were better. When I tried it.....couldn't conceal the disappointment. We drove to woolworths and bought a pack of regular tim tams and the red velvet ones, just cos.