vRA/VRO/vCenter have a few gotachs, so far I have come accross these issues.

• When deploying a VM to a DataStore Cluster(multiple disks), vRA Spesify only the datastore cluster and leave it to the vCenter to select the spesific disk. However vCenter does not select the disk with most free space. It will choose a random disk, and it might choose a disk with not enough free space.(Failing deployment)
• vRA never checks if the vCenter/DataStore/ESXi host is in mainaintance mode. It will deploy to all these and wait for up to 2 hours (default). If still in maintainance mode, the deployment will fail.
• vRA IAAS template spesifies the template to clone. However not the location. If a template has the same name in mutiple locations in the same vCenter, it will fail.
• DRS (Distributed Resource Scheduling) and SDRS (Storage Distributed Resource Scheduler) if enabled and in automatic mode, might move the VM while deploying, resulting in any workflow require connection to the actual ESXi host will fail (Hint: VMGuest Operations).
• UpdateProperties does only work within the same phase, for the next phase the are reset to previous values!
• If you run multiple instances of vRA/vRO (Appliance), in a failover cluster, be awere that it is not a true failover. Any workflow currently running will not failover to the other node(also goes for EventBroker, so any machine in deployment will stop). If you read the properties of a deployment you will see that the actual node for the deployment is hardcoded into the deployment. Also notice that the failover takes about 30 minutes, so if the running node is shutdown, it will take this amount of time for the system to be back up and running.
• vRA never updates it's database (or release IP's) if a deployed VM has changed IP or VLAN) resulting in stale IP's
• Avoid using VCPlugin in your scripts if you have multiple vCenters connected to the vRO Instance, atleast be careful. Using this plugin to fetch data (EG: .getAllDatastoreFolders) will fail if you have ONE vCenter down (even if you just want to access only the other vCenters)
• Custom Properties, be aware that vRO can handle NULL values, vRA cannot (vRA will actually crash)