I think there are simply too many forums in this web site, it is time consuming to browse through all of them. Feel like a Call Centre where press 1 for this press 2 for that, then press A for this press B for that.
The sub forum are actual a great feature as it helps to catagorise the topics being posted enabling people to view discussion in the area of their interest.
If all topics remained as they once were in only a couple of forums and the traffic of posts remained high then filtering throught the stuff that doesn’t interest you is alot more irritating than jumping in and out of forum rooms.
You may want to try using the active topics tink on the side bar to enable you to scan all forums at once.