https://www.juniper.net/documentation/en_US/junos/topics/concept/vcf-components.html

1- single point of management

2- ECMP , 

3- Plug and play for the Leaves ( discover Neighbor and number of links and aggregate links auto)

4- ISSU

5- VxLAN L2 gw 

VCF any port ?  ( VC use backplane cable  )

An MDT is calculated using the breadth-first search (BFS) algorithm rooted at any selected switch

support NSSU on QFX5110 VCF in 19.3

4x Spine and 16x Leaves ( 20 nodes )

Juniper QFX5100 Overview