switching or routing between aggregation pairs?

[adfsdafs adsfafds]

For an aggregation pair serving as HSRP gateway for downstream L2 access switches, is there any advantage of using trunk between the aggregation pair than simply a L3 link?

If vPC is used, a trunk is somewhat justified because vPC requires the trunk for peer link. But without vPC why not just put links between aggregation pair into a L3 bundle for simplicity and visibility? As I understand per port per VLAN traffic stats is not available on any platform.

[Reza Sharifi]

VPC pair could be used as layer-3 as well.  In addition to VPC peer link, you add an addition link used for layer-3 only or use an SVI from the VPC peer link connection. Deployment of each one depends on the Nexus platform you use.

HTH