As I mentioned earlier I've lucked up on a decent core group of raiders for 10-man stuff.
When 10-mans were completely different from 25 it was fun to complete them because it was different content. When they became mini versions of 25 they were helpful in getting geared up. Then, at least for me, they became a way to finish off instances the 25-man groups I was a part of were unable to. I didn't get a drake because of Immortal? Oh well, at least Undying was well within reach.
And now Cataclysm puts 10 and 25 on the same lockout with the same gear. I've already co-opted the design shift that what I've done in 10 counts for 25. I used to respect the differences between the two. I was in the camp sure 10s are difficult for their own reasons but 25s are still harder overall. But at this point either we outgear the current instances or we have a 30% buff for the ones we don't. It's not like I'm really doing 25s for some sense of grand achievement. So if I get it done in 10 or 25 it's become all the same to me.
That said, while 10s are easier overall, 10s are also the place where you feel more responsibility for how you perform. Since our 10-man really got rolling I've been thinking about how successful we could really be as a 10-man only squad in Cataclsym - breaking away from the guild we're currently in. I'm a pessimist so its no surprise I lean toward us not being very successful. The reason I think so is we need the support of a bigger guild. Essentially more people to choose from.
On several occasions now it seems like one or two people, different in each case have held us back from completing a specific goal. They weren't asked to sit out, instead they were unable to show up that day and we had someone else come in and bam! success. Well recently I have no doubt I was the one holding us back (hoping to get a chance to redeem myself soon!) So I know what it's like on both sides.
Since we're not a guild of superstars we're always going to have our cases of durr moments depending on the fight. If we were just a band of 10-12 raiders I don't think we would have the luxury of pulling someone else in when our links break.
4 days ago