I'd say both of them because both are good routes. But if it has to be one, I'd go with MSB as that will also create extra services on the Aachen-Koln route.
Get MSB because the trains in that route provide extra services in other routes, so when you inevitably get those routes at a later date they will have more content. It’s also a great route in itself. RRO also provides extra services in some routes but not as many. To get the best out of the German routes it’s a good idea to plan to get them all eventually but MSB is one of the most important, so get that first.
RRO is more focused on passenger services, and if you prefer freight, then MSB has more of those. It’s worth noting as others have mentioned though, that MSB adds locos to other routes, including the BR 146 and BR 185.2 for RRO.
MSB for sure. A lot of passengers and freight service. Also will add more services to other german routes. And a good mix of things to do (and different type of services)
Absolutely both, MSB first and RRO after both play very differently and add services to other routes, but MSB more so.
RRO is personal favourite of the two. But I’d get MSB to begin with as it adds more services to RRO when you get it.
