I also used to use a Solid Core door. Now I have 3/4" MDF thats 8' x 2'- 6", but I also have an old Great Planes magnetic board (thin steel sheet) on a portion of it and a piece of glass I lay down for cutting film on. Eventually, I'd like to go the way of Dave Platt and have a large tempered glass surface. The advantage of that is that you can tack glue right to the glass and also use a grease pencil to mark on it, and it cleans up with a single edge razor. I've never liked using pins, ever.