Can you explain how to filter, by checkbox, the current structure of this forum - quickly - and get the information you want?

N800, N810 and N900 are all in the same categories, I doubt they are all tagged properly, what exactly are you going to put a "checkbox" on for people to search by?

The solution regarding allowing Null Searches and just selecting certain areas is a little more feasible.. but you're still going to get noise because they are all intermingled with eachother as it is.