The difference issue with 6 or less is not space. The 42 is an amazingly comfortable boat. You can not go wrong with either of these two options. The main (and IMHO) and only real consideration on which boat to revolves around the flybridge configuration. Whether I am on a 450 in the BVI or my 42 in Block Island if the seas permit, all my guests want to be out in the open (ie, not in what is called the cockpit. The 42 does an AMAZING job of making the helm part of cockpit area more than other cats I feel. This is a huge plus for a cruising couple like myself. It also makes docking in reverse easier to see which I do more often in the Northeast than in BVI (Yes I know there are cameras on the 450). BUT!! Whenever we have guests they want to sit up front, which leaves me either alone at the helm, or upfront with them with the remote autohelm in my hand but ready to run back as needed. On the 450, when there are 6 or even 8 people, I ALWAYS have guests sitting with me at the helm. That is the difference - not the water or the cabins or the performance. If costs were a factor the 42 will serve you well - I love it!! But if they were the same price, take the 450 and thank me later.