EOY ownership
You would probably want to be an II member every year because even with an EOY unit you may be able to trade into an "off" year. This is particularly true if the EOY is a lock off unit which could give you a one week every year vacation. For example, if you want to change to an "off year" vacation all you would have to do is to reserve a strong week in the "on year" (no more than 12 months in advance) then deposit with II and trade into the "off year". The result of this might give you a vacation sooner than your scheduled year. EOY lockoffs can be a great TS at a great price.
As an added benefit of an EOY lockoff you cut you MF expenses in half because you get two weeks for the price of one. When MF get over $1,000 per yr you hear a lot of complaining.