Everyone was thrilled and excited to hear about the RDF in patch 3.3 and the day it went live, everyone was going crazy queuing up for some badge farming goodness. The wait times were below five minutes, even for DPS. My initial thought was "wow, this is fantastic" but that soon changed after about a week. Now I find myself sitting around for 15-25 minutes to get a shot at some badges. Naturally, due to all of the spoiled people out there, I find myself having to replace tanks and healers like mad. Not that we don't end up replacing DPS at the same rate, but it just seems that the system that's in place is incredibly flawed. Yes, there have been quite a few times that I've been the one doing more DPS than the other 2 combined, but that's just because people are desperately trying to gear up to take a shot at higher-end raids. I don't begrudge people for this. Inevitably, you have one or two people in the group saying "I'm not carrying anyone through this" before the drop group. I wonder how many of them were carried on the backs of others while they were trying to get gear and badges. Some groups are destined to fail when the tank just can't do his job because he's still learning or the healer just doesn't have the umph to heal the group. It happens. I don't cry about it. What does irritate me is when the tank loves to tell me how to play my class. As a mage, I utilize all of my threat/damage mitigation cooldown's appropriately and I get pretty hacked off with the tank that makes sure to tell me that I'm not counter-spelling enough, etc.. Do these people think that everyone they group with is incapable of doing their job? It's crazy that I should have to deal with that kind of crap when the group is already destroying the instance as it is. I refer to these people as "Professor" since they seem to know so much about what you're doing. Amazing that they can do their job plus the jobs of however many people there are in the group as well.
Another thing I've noticed is DPS plate wearers queuing up as tanks when they clearly aren't. A warrior in DPS gear, using a 2H doesn't do so well as the tank. To add insult to injury, they love telling the healer that they aren't doing a good enough job or the DPS that they aren't downing mobs fast enough. Enough of the rant on foolish people.
My main beef with the RDF is how it queues vastly under-geared players to do some of the harder Heroic instances. It wastes my time and my gold after having waited an inordinate amount of time waiting for the queue to pop. I can only hope that Blizz tweaks the system at some time in the near future. Those are just my thoughts. I'm sure that others have different experiences.