Collections is a great and must use tool to gain control of your images.
But there are limitation to collections which need to be fixed.
Here is an example
Weddings entered as collection set
Tim and Amanda entered as collection set
1 Wedding entered as collection
2 Reception entered as collection set
i SUGGEST THAT YOU CHANGE THE CODE TO ALLOW YOU TO SORT BY NAME AND KIND TO ANY PARTICULAR COLLECTION SET.
Now when you sort collections by name Weddings is sorted properly, but Tim and Amanda even though it is a collection set to which weddings and reception belong will be placed last in the order under weddings.
My work around is to rename Tim and Amanda to 0 Tim and Amanda Then sort arranges this correctly.
Also I have been unable to drag and drop a collection to a new collection in the etire collection set when it is arranged by sort to kind.
Collection sets has a few rough edges and does not always work properly. I have seen in the above case where Weddings was not list when you checked INSIDE COLLECTION SET. Then I had to restart Lightroom and the problem went away.
Call me just a beginner - I do have 60,000 images which only now after years and years, am I starting to arrange. You see over a space of 10 years some of your previous work was never properly arranged. The beauty of collection is that it will reach into your muddle of images and make a sensible arrangement. That of course requires that you learn how to use filters to find, which does work rather well. I have gone through 5 different Canon Cameras beginning with the Power Shot S10, and find all cameras/dates/contain to be powerful.