Favorite airguns often pass with the seasons as new models are released and our old favorites sit unused in dark corners. Ultimately ending up for sale in the classifieds for someone else to try.
As far as what constitutes a quality post, it reminds me of a comment I heard at a meeting of experts, where one of them said:
"While I don't really know much about it, and may not be qualified to answer, nonetheless I have a strong opinion on the topic!"
That was one of the most honest and candid comments I'd ever said in front of witnesses.
Other than not starting arguments in your posts, or broadly degrading other folks' airgun selections, I think that people appreciate posts with:
New or insightful information, especially on the performance of specific models. Including the sharing of how you've corrected any technical problems you've had.
Newbie questions are always fine, especially after the questioner has done some very basic forum research on the topic. Very broad or general questions like 'what's the best airgun' have usually been asked over and over. Spend 10 minutes to see what others have said. Then you will be able to ask an informed question narrowed down to some specific points which people are happy to answer.
There are several forum categories. Try to keep your questions in the general category for the topic.
There are dedicated forum monitors who review posts and occasionally move one to a more appropriate forum category or very occasionally edit out unsuitable comments.
There are probably a few thousand people visiting on a forum like this over a year, many from countries other than the US. Many of them tend to post and focus on a particular forum. So you'll see a very wide range of posting and language styles. And sometimes, when people are strongly opinionated in their posts, it can be difficult to tell which of the posters have 50 years of good technical airgun experience, and who might have just gotten their 1st airgun as a present and now wants to tell everyone their opinion on how good (or awful) it is.
And some posters, especially the retired guys with time on their hands, apparently just like to ramble on in order to hear themselves talking ;-}
JP