Blackfathom Deep Dish has done it again! We're officially done with Burning Crusade raiding now and will be pushing to 80 and Wrath of the Lich King content soon.
Karazhan was...disappointing. With all 10 people, fights were so easy we didn't even have to do the mechanics. Back in Burning Crusade, the guild I was in on US-Twisting Nether (Diamond Spider) collapsed and disbanded as we were trying to transition to 25-man content (Gruul's Lair). Since I was a new recruit, I never made it to the more interesting fights like Netherspite. Alas, I may still never get to experience those fights fully. They're just tuned to be way too simple with the patch 6.0 stat squish.
Gruul's Lair, on the other hand, went well. We had some problems with High King Maulgar because we didn't have certain classes in our roster. It's also a bit of a complicated fight. Our first try also only had 8 people. Once we had a few more raiders, though, it worked out really well. Gruul himself only required a single attempt.
Magtheridon was also tuned very well. It took a few tries, but we got him down. Pretty sure a lot of the requirements have been relaxed from when it was end-game content, though. I swear I remember the cubes working differently...
For Serpentshrine Cavern and Tempest Keep, we tried using the newly-revised Group Finder to pick up a few extra people. Since we'd been consistently getting only 10-12 people for raid nights, we anticipated the raid content getting out-of-hand like AQ40 had. For both of these, we wound up with somewhere between 16 and 18 people and they worked out quite well. Content was about as difficult as newly-released Raid Finder content. That is to say, we wiped once or twice for some of the encounters, but everything was achievable - even Kael'thas (who was really fun)!
Hyjal was where we ran into problems. Even with a record turn-out and a bunch of people we picked up from the Group Finder, we still needed a carry for the last two bosses (Azgalor and Archimonde). The latter was mostly due to time (we didn't want to leave one boss left for the next night), but Azgalor was incredibly difficult on the tanks and healers. I was confident we couldn't have killed him with the group we had, but I'm not sure how well-geared (or how skilled) everyone in the group was.
Unfortunately, a majority of our guild voted to largely skip the last two raids (Black Temple and Sunwell Plateau). We mostly just got carried through them. They're impossible to do with just 10 people (and very difficult if the ~20 or so you do have aren't prepared). The people we were getting from the Group Finder were pretty frustrating, despite our successes, and Skolor decided the extra overhead of dealing with them simply wasn't worth it for how difficult the fights were.
We'd always intended to get as many raiders on-board as we could, but hitting the numbers required for 25-man content is difficult. The fights here are also tuned well enough that the old end-game content is still challenging - especially if you don't have the people you need. I was surprised at how well the Group Finder was working (there's a large contingent of level 70 twinks I didn't expect to see), but the overall quality of player was still fairly low. Many attempted to ninja loot, swore at me in Spanish, completely ignored mechanics, stood in the fire and expected to be healed through the damage, and so forth.
Regardless, it was still a great experience. I'm still incredibly glad we've got the guild together and I'm really looking forward to Wrath of the Lich King content. I have a lot of great memories from the expansion and, in a lot of ways, it still represents some of the best the World of WarCraft has to offer.