What kind of culture?

There is a certain argument to be made that Highland worlds along Major Routes are uniformly bland, or at least not terribly different from one another. There is certainly a small amount of truth about that, if the visitor limits himself to the orbital spaceport or one of the planetary starports or mega malls of the large cities.
Once one gets away from the port cities, even if one is limited to the transmat system, a much greater array of cultural opportunities become available. For example, on St. Martin there is a transmat portal just across the street from St. Barnabas Basilica which can take you to the Golden Beach on the South Continent, where reef diving is a major pass time. As good as the reef is it is vastly overshadowed by the Great Barrier Reef of St. Philopia's Wright Archipelago. Philopia's St Marys Hospital is renown throughout the County for its work in taking on emergent diseases.
Travel on Port San Benedict is a more arduous, and interesting task. No transmat system here, limiting options to high speed grav train, commercial aircraft or private omnivehicle. Large sections of the world are effectively uninhabited, with vast animal preserves for the native life and large ranches teaming with imported livestock. The Monastery of St. Dionysius in the Andreanous Mountains is well known, mostly for it associated seminary.
WoodSocket is a major pilgrimage destination due to the Shrine of Our Lady of WoodSocket, which is surrounded by the almost impenetrable Rothwell Wood. It is easily accessible through the transmat gate across Blakely Square from St. Martin's Cathedral. The Great North Forest continues to supply lumber for most of the Diocese.
The kinds of activities tourists (PCs) along the Major Route are likely to become involved in are varied, but not necessarily safe. Any adventure that can be played in a modern urban setting can probably be played on one of the Major Route worlds.
Also worlds are politically independent. While most Highland governments tend toward laissez-faire republican union governments there are pockets of Great Compromise Sharia Caliphates, where Christians are required to abstain from Proselytizing, and are not permitted to openly practice their religion. Of course, followers of Islam are bound by the same Compromise in Christian areas.
There are also pockets, sometimes even worlds, colonized by other fringe religious groups, though most have move beyond the Highlands and travelers are going to have to go to the Midlands at least to interact with those cultures.
In all these cases individuals accused of breaking the laws on one world are not likely to be extradited by the governments of other worlds. The reach of the Church is somewhat longer and individuals who have broken canon law are more likely to find retribution by the Church, in the form of medicinal punishments, some of which will have temporal as well as spiritual effects. For example, an excommunicated trader is likely to find a dearth of tradesmen who are willing to do business with him. Even governments might refuse to deal with his company, out of respect for the Church, and its position.
A world under interdiction is likely to wither on the vine, as no commercial outfit will do business with them. Such worlds have typically broken some serious precept of  Natural Law, of the sort that even non-Christian members of the Great Compromise believe they are a danger to themselves or others. Examples include approving of abortion, child sacrifice to a false deity (such as convenience or greed), involuntary  human experiments, dangerous culturally supported promiscuity, biological weapon experiments or free roaming nanotech. All of these practices have been shown to result in societal collapse, unnecessary human deaths, and dangerous moral pollution of other worlds.