Actually, rather impressive numbers. Ones that made me think back to epics Blackrock Mountain MC/BWL raid clashes.
The bulk of the fight is spent in phase one, where Mole Machines shoot up, and adds pour out (think brewfest dark iron dwarfs). The more common type of add group, is 1-2 casters, and 1-2 weak melee. The less common, is a single painful-whirlwinding vyrkul. You kill adds until all four harpoons are rebuilt by NPCs and launched (think UP) - bringing the big old dragon down for some pain. Each time you bring it down, you have 30 seconds to get her closer to 50% (whereafter she stays grounded). Oh, and the whole time, fireballs are raining down - leaving superdeadly flames.
We used three tanks to grab groups from mole machines, and one to grab the vyrkul. I found warrior to be pretty ideal for the job - Thunderclap them at the machine, then toss a shockwave stun (all the dwarfs are stunable). Shield Bash or Conc Blow the casters to help on interupts. It did make me consider glyphing cleave, though - since the groups are often three large. When Razorscale was on the ground, I poped intimidating shout to give me some breathing room, while I sundered her up and contributed some dps.
Problems mostly came from people getting double or tripple fireballed, and thereby gibbed. A few people down, and we'd start getting overrun, lose more, ect. Not sure how to mitigate this quite yet, but I've got some research time before the next raid.
We eventually headed to XT-002, to get a feel for areas that need research for the next boss. The only thing I have to say about him, is OUCH. Normal melee swings from 20,000 to 25,000 damage, and I've got as much armor layered on as I thought possible.
He seems overall easier, though. Similar to Astromance Solarian / Baron Geddon, with the whole get-the-hell-out-of-the-raid-if-you-have-a-skull mechanic. We can deal with the incomming damage when we pay attention - I think we're mostly just learning how to do the other phase at this point.
So my first real impressions - is that this place is going to be a blast. I recognise that I've been spoiled on easy content, and now there are some real chalanges - ones that are early in the dungeon to boot - that we will have to spend time working around. With some luck, this content will have some major staying power.