I have started to notice this occasionally too. Looong pause between 1st and 2nd. Doesn't happen reliably but it does happen. Never had the juddering though.I have looked into the ombudsman, it does not appear to be very straight forward, but looks like the route I will have to take, if this does not get sorted soon.
I can safely say it is not down to the DCT as, when it is running as it should, it works fine. There is no delay when accelerating from low speeds, even if it is in a higher gear than expected. Also, when it is not running as it should, which appears to be more often now, it can hesitate, be completely unresponsive or even shudder when I try to accelerate. I am only talking about a slight acceleration, not trying to go fast quickly. It also does it from stationary, i.e. pulling out from junctions, when it is in 1st gear, which is one of my biggest worries.
KCS, who appear to be just call centre staff sitting at a computer quoting what they have to say, and not listening or caring what the issue is, will only listen to what the dealer tells them, I have asked them if I can take it to a proper independent mechanic, but they said no.