If I were you I would go for highly-detailed tracks which come in a variety of conditions and ballast colours to suit different landscapes. A good track set should come in (at least) shiny and rusty versions, a better one would have weathered and unweathered versions to go with those versions too! Besides, multi-track splines have a long list of disadvantages, such as all the tracks go in the same directions and you cannot create junctions/turnouts on them. Although tracklaying is slightly faster this way, the extra time spent is well worth it.