Is it possible/recommended/appropriate...

[Dean]

If buying into DVC means that you aren't guaranteed a room with a bathtub anymore without paying extra, those with young children and those of us with medical needs for a tub (arthritis, for example) would appreciate knowing that.

Whether you'd be guaranteed a tub depends on which unit type you have but for studios, you would NOT be guaranteed a tub. For 2 BR you would have the garden tub but would not be guaranteed anything else. About the only area where DVC puts much effort into as a system for room requests is for medical issues. However, if there are more HC rooms than reserved as such and the resort is at an occupancy such that those rooms are needed to satisfy all reservations, someone will have to have a HC room that doesn't need it and may not want it. You'll hear some say "they don't want to take one away from one who needs it" but that doesn't happen unless they couldn't get a reservation at all during the time in question. Just like the rooms with poor views, etc, someone has to get get a given room.