LOL, 10 hours every day is casual? :P
Actually my reason for not being at the top all of the time was because I loved my guild and it was considered a family raiding guild. We still raided every day, but it wasn't really mandatory like some hardcore guilds. We also didn't use DKP. I could have joined the top guild at any time, but they were mostly just asses. Though, my guild was 2nd or 3rd on the server for most of the time we were there. We were also one of the longest lasting guilds (just recently broke up), mainly due to the awesome people in it.
Sorry to derail the thread a bit. I am excited to try out this instancing code when I get some time. Hopefully in the next few days I will try adding and compiling it and I will report back on my findings