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There are upvotes just based off owning and holding CATS, no upvote service.

there is an upvote-service tied to the CATS-token, if you are referring to that.
1 CATS-token (get it now on steem-engine as prices are low as f**k...) produces 1 KITTENS a day (same thing here ;p ), but also grants 10% upvote-value (i think, please correct me if i am wrong) from the bot if you use the "neoxag"-tag when creating a post (as "neoxag" is a generic tag, associated with www.neoxian.city). You just need to have the CATS in your steem-engine account to be eligible for the upvote, no staking needed.
the KITTENS serve as a sub-currency, so to say, because they can be traded for cats (current rate is 24 kittens for 1 cats still, i think), but not (yet) traded in for additional upvote-value (wouldn't that be a nice feature?).