No, the results should be the same regardless of the amount of nodes in the network. The only things that change are:
1) Security and credibility. More nodes brings more security and therefore more credibility
2) Depending on network settings, possibly more uncle nodes and therefore possibly a bit more centralization. This also depends on the network - if there are only a few nodes which always get their blocks into the canonical chain someone might consider the network somewhat centralized. But uncle nodes still contribute to the network even if they are not part of the canonical chain.
The time to reach consensus depends on network propagation time and similar issues. The network always reaches consensus eventually but the only question is how many nodes end up working on uncle nodes and how many get into the canonical chain.