There is a delicate balance between segmenting the forums enough so that a given user doesn't need to look at posts not "interesting" to them (e.g. If you don't use the SX, don't check out the SX forum) and conversely, making the forums too fragmented, and as a result it's hard to know the best place to put something.
As an example, should someting for a prop retro game be in the Prop forum, or in the Hydra? While if you're not using the Hydra, it seems obvious to put it in the Prop forum, but what happens of the specific "gamer" that has the answer to your question only hangs out in the Hydra forum? What about all the other "non-gamers" having to read/filter out something they really don't "care" about?
Was it right to make a new forum for the Prop Scope vs having that in the Sensors forum? Don't know.
Should "Wireless" have included, or be expanded to include all forms of "external" communications? Would we want to end up with a separate forum for "ethernet" communications? Should all of this be in with "Sensors" and rename "sensors" to "periphials"?
Why isn't there a separate forum for Video on the prop?
Now, don't take all, or any of this, as a specific suggestion, just a few thougths to ponder. I have seen, both in the hobby and professional world, forums fail by both being to fragmented, where each forum was too specific, and hence useful information harder to find/get, and also by having too few forums, and you couldn't find the post you added yesterday because of all the other "junk" in the way.
Thus far, we've seemed to have a decent balance. Watching post numbers, etc., would be a good tell tale. If you don't see a significant number of posts in a given forum, that might be an indication that consolidation would be in order. Likewise, if the count is exceptionally hight, there MIGHT be a case for breaking the topics up.
My personal thought would be to error on the side of too few forums. The danger of fragmentation is gernerally higher than the opposite.
All of the above, and about $6 - $10 (depending on where you live) will get you a really nice cup of something at Starbucks.