Hi @mr.richardb,
My understanding is that the hardware simulator is no more :(. So you can use the VM but at the end of the day the simulator has no data plane. Great for testing scripts and moving around in the interface, doing training and familiarization, but not so good for testing connectivity etc. The always on Devnet Sandbox gives you this if you don't need a dedicated resource. Handy for a quick test or to check on something if you don't have your own fabric.
I keep a list of lab rentals when I need more than a simulator but there is a cost associated with this option.
https://gratuitous-arp.net/the-hunt-for-a-cisco-aci-lab/
If you have an ACI fabric, I always recommend building out a "Sandbox" Tenant and attaching it to an existing lab or to some older equipment for testing and training but even that has its limitations.
I looked at getting an ACI mini kit but that was a bit too much for my budget.
You may be able to test some functionality in the DCloud labs...I'd see how far you can take those. They usually don't provide a complete solution (for me) but its something.
