I'll try to throw my 2 cents of advice as a somehow novice user.
As many of you, I came across HD during a search for big and reputable hosting related forums. I had a neat list of around 30-35 forums and decided to start only with the major ones. As a starter, the first thing was to find suitable threads to contribute. At first there seemed to be plenty to talk about and I tried to enter discussions that are no more than a month old, so I can be sure there was a chance for the discussion to continue. The first few days worked great and HD was in my top 3 list for sure.
Now, as this is only one of my daily tasks, I had to work on a procedure that was not time-consuming and yet letting me be helpful as I can in the forums I chose. So what I do when I login is first check my subscribed threads, offer some additional responses when possible. After that I go to the New Posts, browse through all topics and choose the ones I think I can be useful in. So what I saw in time is that I found it harder and harder each day to find new, fresh material, where there are actual opinions raised and not just some copy/pastes and one-liners. I just don't feel I can add ANYTHING to such posts and I just leave them be. After a strong start I feel as if now I'm not getting more than a few interesting threads weekly and deliberately limit my posting so I can keep the value and relevance of each post.
Now, a very interesting point that you brought DigitalPoint to the discussion, as this is the example I was about to give. Mind you, this is one forum I initially didn't even try from my list, but later decided to give it a try. As you are much more experienced in the forum field, I see that in the past this forum held absolutely no value to quality posters, but indeed can see a difference now. Sure, there are still many users that do the same copy/pasting exercises. Yeah, I don't quite like their Established Member status that you need to get to post ads or like posts (the requirement is actually Certain Number of Days+Posts+Likes from 3 different Established Members). But at the end of the day I still find a larger number of quality material to comment on. And its not even because the forum is much bigger, with much more sections - I still predominantly use the Hosting, Domains and SEO section that you have here.
So what am I trying to get across? I do like HD, I really do, its still in my top list, but the amount of low-quality fluff posts have to diminished somehow. Would that happen with different rules for newbies? Probably not, the 14 day requirement for Ad posting keeps a big part of this mass away. Most of those users want to get to that part as fast as possible. Having a limited daily post count, even though requiring more consecutive logins, still speeds up the process of getting to Ad Posting point. And that will likely cause a reverse effect. Not aware of the HD internal staff and how busy they are, but opening room for new moderators (even established community members) might tighten the security a little bit. Its a matter of catching those "fluffers" faster and stop their access during their early invasion. More time and effort is required from this plan but I do believe it would be for the best
Edit: Oh yeah, Merry Christmas to everyone too, hope Santa has brought you many smiles from people you love