This isn't about efficiency or anything that needs to be fixed like most of the threads here. I just had a great experience and wanted to post about it.
It's actually a little embarrassing since I'd played since alpha and never really tried to play in a coordinated party before now. When I was in one everyone just sort of randomly used their own abilities like they were solo, but in a big group. People fiddled with battle regimens but we never used them in any coordinated manner to fight difficult targets.
Yesterday I joined a real SP party for the first time, and it was amazing! Battle regimens are a great improvement on FFXI's skill chains, especially the way they fill a little list so you can tell when your turn is without macros and calls. We were able to use them to fight things far above our own ranks. I got to use most of the abilities I'd learned as a thaumaturge but had barely touched because solo you just spam the same four things on everything. I also was able to witness other classes timing their abilities, holding adds, and managing their enmity, which made everything in general look better and make a whole lot more sense than levequests ever did. MP management between the new costs of spells, having to roam around to keep fighting, and unique abilities to regain MP versus other MMOs I've played before kept things really engaging (and battle regimens helped with this too, being much more efficient than single abilities). Unlike an FFXI party, we got to fight all manner of interesting enemies, from salamanders to skeletons to ahriman.
I know this is probably extremely old news to everyone who hit rank 50 (multiple times) during the leve abandonment exploit farming, and especially now that people are clearing the challenging new full party dungeon that was added. I had a blast though, and the whole thing renewed my interest in the game in general. I can only hope the rest of it gets fixed up (like searching so people can party more easily) well so that other people can experience it, and so that I can continue to do so. I feel the game is "worth saving" just for this.