I think a part of the issue with "paragraph RP" is the sheer lack of people who understand that a paragraph can be 1 sentence long. 1 word, even.
And the issue with group RP is that if you try to be inclusive of everyone, everything, every detail, you're going to be there for 3 weeks writing a post. It's why you can read 500 words that include nothing but descriptions of a character's eyes and acknowledgments of other people's actions. Like "/me notices the man take his gulp of paga with her cerulean blue eyes" bla bla bla forever.
If the group is relatively small, say, 3/4 people, and my character isn't known by them, or if there is something particularly special/odd about my character that day, then my first post or two might be a bit longer to paint a picture of my character for these people who haven't met him/her, before falling into shorter action/speech posts. If they know my character well already or the group is large enough that they wouldn't be likely to get the sort of nitty gritty details that are included in a longer intro post, I'll just post a bit shorter.In any case, I'll usually try to (somewhat) match the RP style of whoever I'm RPing with. I can still be a bit verbose, sometimes, but I don't get any complaints and the people I have fun RPing with invariably come back for more, so I'll take that as my confirmation.
These are both (full) posts of mine from the last couple of days:
I do find that if you have 3/4 good
(IMO) longer-form posters in a scene, the flow tends to go better, with each typist writing continuously as things happen so they end up with a coherent post that, while longer, is full of relevant information or interesting details/hooks. The longer post above was posted 5 minutes after the previous post in the scene, and 5 minutes was probably the average "wait" time between posts. And while, certainly, you will often meet characters that don't play to your personal character's IC agenda (like Tantus being annoyed by the typists of slave characters wanting to RP), I think it behooves us to be inclusive of other people and look for their hooks so as to pass the ball, even if not for our own benefit.
Having said that, the longer post above has its limitations. Where my character asks another a question, "are you being trained" - there might have been a reaction that would have changed the course of the scene and made the scene change course entirely, like a curt reply, a sulk, a laugh. But perhaps that typist is then more reluctant to make such reactions when mine has already moved on to acknowledging the next person "in turn". The flip side is that it becomes a bit messy, and (again, IMO) loses some depth, and some inclusion. So I think it's subjective. You judge the scene, you judge the situation and your fellow players, and you make a decision on what sort of post you think will better push along plot for yourself and others - and sometimes that will be a long, descriptive post, and other times it'll be a "/me watches in silence" while you let other people take center stage.
More than 4 people in a group and you really should be shot for trying to include everyone and everything and write longer posts.
As for which I prefer - Anything up to 3/4 people in total can be a blast. I like a good deal of 1 on 1 with the most central folks in my character's life (usually an inner circle of, I guess, 3/4 people?). And I find larger group RP (tournaments, celebrations, courts, "magnetic" scenes as described by Glaucon) confusing, largely irrelevant, usually, but good for picking up "hooks". Like, maybe there's nothing immediately for me within a large group scene, but I notice a free woman with a (emoted) rich-looking dress that's a bit threadbare in spots and lightly tattered - and I overhear her introduce herself as Lady Victim McPoorpants - I post about noticing her and then seek her out later to offer to pay her for some shady dealing I need done, having inferred that she's in desperate need of coin.
I guess my split would be 70/30 1-1 to group, but for groups larger than say 4/5 people, I only want those once every month or two and find them burdensome if they happen more frequently than that (as they often do!)