My guild does strictly 10 mans, but I ran a few pugs last week healing for 25 mans and I realized that I absolutely hate healing in 25 man raids but healing in 10 mans is awesome. I don't know why there is this difference but I was wondering how the community in general feels about these two different modes. Here are a few of the things that bugged me about 25s:
Personal responsibility seems to go out the window. On most of the encounters there were a small handful of players that would just fail horribly at the mechanics but the fight was still doable. In 10s usually if more than one person died it would be a wipe, especially if it was a healer/tank. One thing coming to mind was on chogall a tank dying 3 times and repeatedly battle ressing, and it was still one shot. (yes I know I was healing so that makes it partially my responsibility but we didn't have any "healing assignments" so there was some confusion on who was to focus healing on tanks during add phases).
Playstyle - I had to heal completely different than I usually do. I couldn't utilize my mastery bonus because there was just too many targets to heal. It seemed like blanket rejuv and wg on CD was the only optimal healing strategy. If there were problems the only answer was to spam more rejuv. In 10s the fights seem much more dynamic - I had to pay attention to who other healers were healing, when to focus on raid, when to focus tanks, when I could slow down and allow some regen.
Division of responsibility - I don't pay "too" much attention to the intricate details of encounters unless its one that is "progression" and we wipe a ton on - but it seems in 10s everyone has to be better at their class and perform the role of multiple players. If someone needs to do interrupts, thats all they need to do for the fight. If someone needs to raid heal, thats all they need to do is spam raid. If someone is tanking a particular mob, all they need to do is worry about their mob. If you don't have anything "to do" all you need to do is spam your rotation until the boss is dead, completely oblivious to what is going on. In 10s there is not the luxury of being able to devote a spot to one specialized role. If you can't use an interrupt focus macro on halfus while dpsing appropriate targets, the raid will not have the dps needed to get through it. It seems individual ability to play their class to their fullest use doesn't mean much in 25s.
This is purely from a healing perspective. It seems that aside from more loot/VP, there is no real reason for me to do 25 man content.