"EIGRP named mode automatically uses wide metrics when speaking to another EIGRP named mode process. No additional configuration is necessary, this is automatic. So if it's speaking to a traditional EIGRP process, it uses the old calculations."
Is there a quick way to tell if a neighbor is using wide metric?
when you check the show ip eigrp topology table for a route/network the calculation will be in pico seconds and not microseconds
You should try use one mode or the other not both reason behind it is the metrics will be sent on classic and new mode until a decision is made by each peer what to use so your increasing resource use if not required in bandwidth when there's no requirement oif you already know what's supported , any redistribution pe/ce will all use classic. like Milan said classic - new the classic will win and the peer will revert to classic mode to be compatible
v8 and above eigrp supports wide metrics , show eigrp plugin will give you the version your device is on