One of the considerations in choosing a Use Year is cancellations. If you never cancel a vacation, this won't matter. But if you cancel a vacation (early enought that the points don't go into holding), it would be nice to have the option to bank points.
If you have a February Use Year, you may bank points up to September 30. If you scheduled a February vacation and then had to cancel (more than 30 days in advance), then you have most of the rest of the year to reschedule and up to 10/1 to bank. If you scheduled an October vacation and then had to cancel (more than 30 days in advance), you would have only Nov-Jan to reschedule and only until 10/1 to bank, which would be kind of skinny.
If you had an October Use Year, you may bank points up to May 31. If you scheduled an October vacation and then had to cancel (more than 30 days in advance) you would have all year to reschedule and 8 months (May 31) to bank. If you scheduled a February vacation and then had to cancel (more than 30 days in advance) you would have February through September 31 to reschedule or up to May 31 to bank.
If you travel in October and February, an October Use Year would give you more leeway to reschedule and bank.
Bear in mind, that 5 years from now, you may be traveling in May and December and all this thinking would go right out the window.