If you have reliable vacation planning, UY is not going to be a big deal -- it's just something you manage.
The importance of UY has to do with banking deadlines. You can currently bank unused points during the first 8 months of your UY. The difficulty arises if you make a reservation tying up your points, and then have to cancel that reservation after your banking deadline has passed. In that case, you would have points that you couldn't bank -- "use or lose" points.
If your vacation plans are pretty solid, you really don't have to worry much. For example, we had an October UY in an account shared by three families, all of which had school aged kids (and one teacher). Needless to say, our vacations are mostly during the summer school break. But, once set, we rarely cancel.
In more than 30 trips, we have canceled exactly once after the banking deadline. However, those points were almost immediately used by another family member, making the banking deadline a non-issue.
If you have complete flexibility in picking UY, I would follow Vicki's advice above and get a UY which allows maximum flexibility.
But if you are buying resale, I would not pass up a great contract because of UY. Just be aware of the implications of UY and manage it like you would any other aspect of your
DVC account.