Why not buy the whole thing?

Until recently, the only choices for an affluent vacationer were to buy a vacation home and take on all of the responsibility of managing a property which was far from their primary home, or purchase a share of a vacation property and deal with the schedule restrictions which effectively required vacations be scheduled months in advance.  Affluent vacationers often chose to buy a vacation home simply out of frustration.
Recent real estate trends, however, have made resort home prices give even the most affluent reason to pause.  Factor in year-round maintenance, taxes and all the vacation time spent preparing the home for use and then non-use and the choice to buy the whole thing becomes even less appealing.

What is the difference between timeshare, fractional, residence clubs, destination clubs and Condo Hotels?

Timeshare is simply the shared ownership of a property and was the original alternative to buying a vacation home.  Timeshare is the least expensive option, but also has the least flexible use model and rarely increases in value.

Fractional is a general term for a number of different use and ownership models.  Fractional products can feature floating, rotating or fixed calendars and can be deeded or non-equity.  The main types of fractional products are Residence Clubs, Destination Clubs and Condo Hotels.

Residence Clubs are generally deeded fractional products giving owners access to a home in one location.  They characterized by luxurious residences, complete service and amenity packages and higher prices.  Residence Clubs typically feature an 8:1 Member to residence ratio and sell anything from fixed weeks to a floating calendar to a rotating calendar.

Destination Clubs are non-equity fractional memberships giving members access to homes in many locations.  They are also characterized by luxurious residences, complete service and amenity packages and higher prices.  Destination Clubs typically maintain a 6:1 Member to property ratio and allow members a certain number of days/weeks per year, sometimes allowing more use on a space available (short-notice) basis.

Condo Hotels are branded fractionals and can be single-location (like a residence club) or multi-location (like a destination club), depending on the operator.  These are characterized by the brand and are generally the same in every location, offering a reliable branded experience.

What is an Epiphany Club and how is it different?

Epiphany Clubs are non-equity fractional memberships.  Epiphany improved on the existing residence club use model by incorporating elements of the fractional jet and country club models.  Epiphany has eliminated calendars and reservation systems.  Epiphany studied use patterns and fail rates (inability of members/owners to secure a desired reservation) and built a capacity management system limiting the member to residence ration to 5:1 and ensuring availability, even during peak holiday times.