I primarily use Poser Pro 2014, and am slooowwwly in the process of moving to Poser Pro 11.
Mirrored poses are nice. I have to do a lot of editing when I try to mirror myself in Poser Pro 2014 because Poser doesn't recognize the additional body parts. I know there is a script (mirror my pose) for mirroring, which was posted somewhere here. I finally got it working in Poser Pro 2014. I must have installed it in the wrong version of Poser the first time. So, while users can create mirrored poses in Poser, they need a third party utility to do so with figures that have more body parts than Poser expects.
Partial poses are also nice. However, Semidieu's Shaderworks Library Manager 2 will let you apply partial poses, and it's currently in the closeout sale at RDNA. Cheap. Real Cheap.
I also prefer poses to be listed in the library by pack/collection name. However, I also categorize all products by figure, so I generally just pull out the product folder from the zip and drop it in my Poses folder under the figure (Runtime / Libraries / Pose / 01 Dawn / 05 Poses), so it's not really that big an issue to me. Currently, HiveWire poses are just installed under the appropriate figure (Dawn, Dusk, Luna, etc.), but with V4 and M4 I ended up also categorizing the types of poses (Casual, Couples, Action, Caster, Warrior).
Expressions are cool, but I'd rather they be supplied as a separate expression than part of the pose. I'm perfectly happy if no expressions are not included as part of the pose or as an expression. I find most expressions are overdone. People who SMILE BIG make me wonder what nastiness they are up to ... so I rarely have my characters smiling. Then too, I'm not much of a smiler myself. If I am ... most likely the scorpio is thinking up evil things to do to people who make my life miserable. Though sometimes, I do smile just cuz something nice happened.
I also prefer that the product folder match the store product name. If not, I rename the folder. It REALLY bugs me when the name of the product folder doesn't even come close to matching the product name.
I also like to see the whole pose in the thumbnail. Which is one reason I have my thumbnails display as beeg as Poser will allow me.
Yeah. I like to see multiple angles, but it's not a deal breaker. Promos are hard work!!!