White Dwarf 388, which was a nice change from the standard 40k scenarios. We rolled for the Breakthrough mission, which had each side trying to break through the opponent's line in a doubles game where my Ulthwe allied with Chaos against Black Templar and Necrons.
The random tables for environmental effects were cool, though lack of familiarity slowed things down a bit as we searched the tables and tried to figure out how to use our shiny new effects, but I think with a few more games of practice we'd be able to fire through quick enough.
Looking at some of the tables I'm pretty keen to fire down my Necrons with this at some time, since several of the rolls will provide good synergy with my Writhing Worldscape C'tan, but even with my Eldar we had some good results, mostly damage to enemy units coming across the field.
And in true Eldar style I managed to grab us a last minute win with a quick turbo-boost into the enemy deployment zone for a win of 14-11. Hurrah for fast skimmers and jetbikes!
The main thing I took from that game was just that it's nice to be playing something other than the standard 3 missions. Anything to shake up the game in these dying days of 5th Edition is good in my books, and I look forward to seeing what GW offer us in the way of missions for 6th.