I've only just started doing dynamis, despite it being around since before I was playing. My main reason for avoiding it in the first place is because all I hear is people complaining about exp loss, crappy drop rates on this and that, etc, etc. Also, I was intimidated by the whole idea of applying to shells in the first place, I guess.
After recieving some encouragement, I decided to finally give it a go. I joined Aristocrats, a shell that I've got a large bunch of friends in so it wasn't too discomforting and unfamiliar although the runs are rather late for me, I can put up with it for now.
My first run was in Bastok, which from what I gathered was one of the easier runs. It seemed very hectic with 40 or 50 people in the zone, running around, mobs all over the place but at least everyone else seemed to know what they were doing. At first I was in a party with a single WAR, so I didn't have a great deal to do apart from keep him buffed and alive and sleep the occasional mob that the blms missed.

Loot whoreing already?
I got put in a BLM party later to commence the soul-destroying process of a 6-man refresh cycle, but it wasn't all bad with MP refills and Aspir on the statues allowing me to nuke on occasion.
Only thing that troubles me in Dynamis is targeting stuff quickly through the mass of players/mobs, probably best to employ stnpc in my important macros (Sleep/Silence).
So we end up killing the main boss for the clear, and then proceeding to empty out the rest of the zone with 30 minutes to spare (hardly a surprise considering how many people were there).

Next run was Windurst, which got a little frustrating being regularily hit with paralyze and silence, along with sleepga at times. It was all going quite well, up to a certain point where we had to pass something called 'death house'. We were told not to aggro the mobs there, as we wanted to get pass and kill an NM for the boss to spawn before we fought the mobs here. So, I behaved myself and snuck past undetected.

Unfortunately, not everyone did the same resulting in an asston of mobs pouncing most of the alliance while we were split up and unprepared. Most of us managed to make it to a safe spot to die and reraise and made a feeble last stand there.
We lost a huge chunk of time thanks to this balls-up, but fearless leader Xarpei spings into action, sac-pulling (basically sacrificing himself so we can pick off one mob and avoid the adds) the NM we needed to kill, and then sac-pulling all the death house mobs away so we could get past to the bridge and avoid fighting them. He missed a few of the house mobs, so we had to take those with us and kill them at the bridge. In the end, most of the house mobs linked to those we were fighting at the bridge and we ended up killing 90% of the mobs we were trying to avoid in the first place.

Everyone was reassured to see how focused I am during pulls.
In the end, we still managed the clear and had plenty more time left over to kill a bunch more mobs.

Most recently, Dynamis-Jeuno.

Once again, I demonstrate my unending vigilance.
Killed some gobs, got paralyzed by pets, fire alarm went off just before we stormed the palace place so I had to afk for most of that. Half expected to be sitting beneath a sea of popped mobs when I came back, but I was ok and caught up easily enough. Was the first time I saw some RDM af drop, and I actually had the highest points out of the people who wanted it, hurrah.

'Spikes' enhancement is nice, since I do alot of bloodtanking in campaign and skillup soloing, also I still encounter alot of nuke resists on mobs that are very tough and over, so the +skill is very welcome. MP is cake, DEX is....uh, DEX. LolDEX.
The run went a little messy towards the end, but we got the clear easily enough again, putting me at 3/4 for Beaucedine Glacier access. I think the next run is Buburimu, which I do have access to having completed CoP 3-5 so I'm looking forward to trying that one out. Hopefully a Sandy run comes soon. :0
That's all.