Romania wins on latency to every major CIS city. Moscow: 52ms from Bucharest vs 95ms from Reykjavik. Kyiv: 30ms vs 105ms. Minsk: 48ms vs 110ms. Almaty: 75ms vs 145ms. For applications where response time matters - streaming, VPN endpoints, real-time communication - Romania is the clear choice for a CIS user base.
Iceland has superior latency to North America and Northern Europe. If your service is used by Russian diaspora in London, New York, or Berlin, Iceland's network advantage for those routes partially offsets Romania's CIS advantage. For mixed audiences, consider running Romania as primary with Iceland as a secondary CDN or failover node.