And, there hasn’t been a waitlist for some time now. At least in California. I was up and running within 30 minutes of starting my subscription, and can cancel any time.
And, regardless of the exact implementation, the Shadow approach is infinitely more desirable to me than the complete lock in, and limited selection, of Stadia.
And yes I know you use your own games.. But it's not suited for casual use for me. I use plutosphere instead. That's only intended for VR but that's all I use anyway :) Plutosphere is also a "PC in the cloud" but you pay $2 per hour and a $10 monthly fee if you want persistent storage. No sign-up fees though. But its pricing is pretty ideal for holidays, whereas Shadow PC is now completely unviable for that with the activation fee.
First they had an almost year-long waiting list. Now you have to pay a hefty commissioning fee.
For me that makes no sense as a cloud setup. The benefit of cloud is paying when you need it (like when I travel and didn't bring my PC) and not when I don't need it.
Stadia did offer that but because you had to pay for the games it also wasn't worthwhile.
I use plutosphere now for VR when I'm traveling and that's great and not too expensive. Still a bit buggy and slow to boot the machines though.