I have been really happy with multiple collections feature. For me the MOST important thing is knowing where my cards are physically located. My collections are set up for large boxes, small boxes and binders. I use the comment field to record which box a particular card is located. I keep my Main Collection empty. I made a coupla trades recently and the cards I got were added to my Main Collection. It was easy to then remove them. Those cards will get added to the proper collection whenever I come across them as I add cards to my collections. I still have a long way to go but I am very well pleased with how I have utilized the system here at TCDB.
I also use the stats feature. That allows me to see my collections of certain teams and certain players. My boxes are not set up by year or team or set or any of that kind of organization. They are randomly put in boxes and the database allows me to quickly locate a card if I want to look at it.
We all live in a Perry Groves World...