Lots of good points in this thread. I agree that the double-edged sword of this change S-E is proposing will potentially cripple the efficiency of current Dynamis groups, but most of this is all speculation at this point. I've been doing Dynamis off and on for the past 4-5 years and the old system worked quite well. However, it seems to be more of a chore to me than the rewards (or in my case, complete LACK of rewards due to miserable luck ::shakes fists at Duke Berith:: ) promise to pay off. Granted, Dynamis currency isn't impossibly expensive to purchase, or rare enough to make farming it daunting (relatively, at least), it IS grossly inflated relative to the cost and effort necessary to obtain it. I'm actually interested in the changes coming up as well as the promise of a more casual approach at this content.
I would like to propose a 'Have Cake / Eat Cake' solution to the situation. Whether it's viable or not is irrelevant to me at this time because I don't claim to know or care about SE's server situation.
They can make Dynamis both instanced AND open to all. Keep the current form of the event intact, and as is, but with the new additions and modifications except keeping a 3 day cool down to avoid server monopolization. Employ a reservation system similar to the reservations required for Ballista or Brenner (I know that time is volatile in Dynamis, but not discussing in-depth mechanics here) requiring participants to have a copy of the reservation to enter. This will keep Dynamis linkshells able to operate as before without impacting efficiency. On top of this, have a SEPARATE instance of the zone with the 'open to all' framework in place. In order to encourage team play and to avoid the lazy factor, make the drops in the free-for-all zones moderately more infrequent and difficult to obtain than the dedicated zones. This will allow for more casual players to enjoy Dynamis at their leisure, but not invalidate the efforts of the more dedicated player bases.
Also, in order to allow both player bases the same opportunities, allow the players on dedicated zones to play in the open zones 24 hours from their previous entry regardless the instance of the prior event.
Just my suggestion. I figure that would make things enjoyable for all. Sorry for the length.