Currently Pinside machine ratings have four broad groups: Game Design, Artwork, Sounds and Music, "Other Aspects" (Game Lighting, Lastability, Theme, Fun).
I'm proposing the Pinside braintrust consider adding a fifth group on aspects of Ownership. These would all be optional for rating a machine.
I notice a lot of the more useful comments on personal-collection machines touch on these aspects, and it's an important factor for both new and old machines alike -- one that may change over time -- that isn't directly reflected in the ratings. Ergo, I think it would be a useful addition to the ratings system.
Keeping with the current four "subratings" limitation, the four subcategories might be something like these (feel free to add your own, this is just a strawman):
(How often does it break down? Does it wear out repeatedly over time and/or have problem hot spots, or is it generally solid and wear-resistant? Is it engineered for long-term ownership, or was it part of the throwaway era of manufacturing?)
"Ease of Repairs/Maintenance"
(Are parts easy to find/source? Are the parts one needs to maintain easy to access? Are repairs straightforward, or tricky? Are software updates, where applicable, easy to implement?)
(Is there help available -- will you be on your own, or part of a big group of owners, or somewhere in between? Does the manufacturer still exist in business and does it offer active support? Are there software updates, where applicable?)
(Does the machine tend to hold its value over time? Is it expensive to own? Is the fun factor worth the trouble of owning it/maintaining it?)
Another potential ratings sub section:
(Can the machine be modded easily? Are interesting mods available from the manufacturer or third parties? Does the machine lend itself to interesting modifications?)