PHYS:
Pro's - Dedicated HW (in theory more stable base/less to go wrong/reduced complexity)
Con's - Locked into only doing one thing w/ that piece o' HW, less flexible WRT multiple-use's for that HW, phys HW is what it is, can only expand to what system supports
AIO:
Pro's - Flexibility, agility, multi-purpose nature of 'doing more w/ less', 10G networking included via vmxnet3 if doing a single AIO storage config (in memory network transfers, super fast), can easily add resources (CPU/memory/network) w/ a simple shutdown/reboot, no waiting for HW to arrive
Con's - Risk of PSOD from other VM's crashing ESXi hypervisor hosts and taking down your AIO (very low risk but a risk nonetheless), system maint can be a bit of a shuffle/balancing act if all your VM's are on your AIO but you need to perform maint (have to sVMotion all VM's/I/O to other pool/stg/system)
I'm sure I am missing some but that is high level.