The nodes I no longer use I use as workstations, I built each (also Xeons), that way :- ) So they won't ever become useless. Some people come and go occasionally through my 'office' and they use them :- ).
As I wrote above, I no longer use Xeons as 'node', but as workstation. So that it is, and I use Rebus, for all renderings. Why:
Convenience: I can upload 10 images and get all of them back in 20 minutes. 8K resolution, it would take 2 days using what...40 i7... ? Why would I even bother building that much capacity.
And I love doing things at last moment, not bothering with scheduling, praying something doesn't go bust, having weak sleep because of anxiety. 20 minutes, and I can close the work for day sleeping like baby.
Utility: I only render every quite few days, maybe once a week at most. Additional nodes would be wasted.
Cost effectivity: No, Rebus isn't cheaper in use than your own farm. Personal render farm will always be cheaper, but it has huge upfront cost and you will never get such capacity as cloud solution, which scales flexibly indefinitely.
And I don't care. I charge enough to make the Rebus fee to be nominal among all the costs I charge clients.
Maintenance: Zero. And it's so damn easy. Single button from inside 3dsMax, and it delivers .exrs into their respective folders on my harddrive. Just amazing....it's easier than backburner. Why would I bother installing/cloning nodes even ? Buying additional licences and whatnot... Saves a lot of time and mental well-being.
I was quite sceptical of cloud two years ago, and even told Adam I don't care for Rebus. But now...I can't imagine using anything else.