Not much help for people running their dev environment in a VM since running two VMs at the same time is quite horrible/impossible even on recent powerful macs.
Put the vms on an SSD and max out your ram. I can run at least two windows vms on a late 2011 i7 MBP with SSD + an express card SSD for vms, and 16 gb of ram
So for a couple hundred dollars, you can run 2 vms at once, or sign up for BrowserStack for a year or two and run waaaay more. Neat setup, but you're not selling it too well.
The cheapest option they offer is $200 a year, my option has no ongoing cost, works offline or with a limited connection, works for locally hosted sites, works for resources I access through a VPN or tunnel, etc.
fwiw, local and VPN/tunneled work - they can set up a tunnel to your machine, at which point the data is entirely in your control (there's a "local testing" category in the support area). And I entirely agree with your earlier points, and there are probably other benefits to having that kind of SSD setup.
But did your setup cost $200? And that includes hardware and software. If you had waited a year, would you have saved $200? (depending on when you bought your SSDs, those alone could be a 'yes').