Respectfully, I feel that if we move too much against courtesy, what there is will fall apart. People's opinions in this discussion are being driven by their own personal experiences with it, and it seems to have mixed reviews--both people who have had wonderful experiences of respect and courtesy and people who have their ire up because of people who haven't been courteous. There are a lot of problems that could be solved with a ground rule of listing WIP models in sandbox posts, doing a board-wide search before your heart is set on a model and also, if you find a model that's been sitting there for months, to PM the driver and work it out. Most of the problems resort from people not talking to previous drivers about that and working out a solution.
But if this system is implemented, I like Toya's model of it. It gives a little more freedom to those of us who honestly don't have a lot of time on our hands and don't want to be impulse buyers but still have a number of WIPs at a time, and gives an amount of fairness to remove claims by people who leave sheets sitting for six months. I also want to see a system that requires some amount of completion on the sheet before claims--however, I'm not sure how that would be implemented since we all work on sheets in different orders. Maybe like, two out of Personality, Appearance, and History have to be completed before a claim can be made? To account for the fact that people work in different orders?
Mickie, your last bit is true, but someone could write up a really fast sheet all in one night and take her model just the same. It's not really any different from the current model claim we have. Honestly, as someone who takes a lot of time perfecting a sheet, I'm a wary of month-long things, for the exact reasons I've stated.