In this. Never used DN before, but should be able to make myself at home before the tornament start.
Edit, because the OP demands it:
I've played for some years now, almost quit when I decided to take up playing again recently. My playing until now have mostly been versus the AI of WC08, WC09, WC10, WC11 and my friends, because I didn't knew of the existence of any online simulators. Such I've not very much experience from PvP, but I've been trying out DN and I'm doing okay-ish. Haven't played any rated yet at the time of writing this, though.
A quick answer would be that, yes, I've played actively in at least one of the recent formats, but with the exception from recent practicing, only versus AI.