DVC trips get addictive - not sure I would be able to limit myself to every other year, though, of course, it can be done and many do.
For me, I feel like with paying the dues I want to go every year - the DVC membership feels more tangible that way. Though, for us, the issue is not whether to go every year but how often can we go more than once a year
Wanting to go even more often is compounded by the DVC discount on the APs
Good luck deciding - DVC isn't worth it for everyone so it is good to consider all the angles.