When you look at buying a townhouse in a planned community, you first have to know what you're buying - how the house is deeded.
There are two types of ownership...
1. Fee-simple. This is the type of deed 98% of single homes have. The deed covers both the land and the structure.
Many townhouse communities have HOAs (Home owners Association), and membership in the HOA is specified as mandatory in the deed.
You are responsible for all repairs to the exterior of your house...because you own the outside of the structure.
The HOA usually owns common ground outside of homeowner boundaries, either open space or often things like a pool, tennis courts, playground. These facilities are run by the HOA, and your HOA monthly dues pay for expenses, wether you use those facilities or not.
Also, the HOA may or may not have blanket contracts for things like landscaping, trash collection and snow removal.
The HOA may also have architectural guidelines that specify what you can do outside of the house(yes, on your property) as to plantings, paint colors, additions, etc.
Your deed gives you ownership of the interior of your house...from the studs in. The Condo association owns the land and the outside of the house..roof, decks, patios and outside walls.
The condo association, which you automatically belong to, collects fees and negotiates contracts for all common areas and things like the pool, etc.
One of the big differences, as far as quality of life, is the fact that your front and back yards are common property in a Condo - and people can and will walk through your yards.
In my opinion there is nothing like a well maintained single family home and much more when one is a financially conservative individual or couple.