I list on Airbnb and VRBO.
There's not that much difference in terms of the "involvement" when either guest or host involves VRBO apart from VRBO has always provided a quicker response to me than Airbnb. VRBO is also less reluctant than Airbnb to become involved in determining and issuing credit/refunds to guests in my experience, citing the contract which exists between guest and host to which VRBO is not party.
However, there are some other quirks to VRBO, such as, hosts can elect to allow multiple payments, a deposit and the balance, say, 3 months before check-in. If the guest fails to pay the balance, VRBO won't get involved and if the host cancels the reservation because the terms of the contract have been broken, then the VRBO penalty will be applied, in effect, your ranking is affected. VRBO like to use the multiple payments as a selling tool but leave the host out on a limb when it backfires. Of course, VRBO collects all of its fee with the deposit - no flies on them!
As with Airbnb, reviews aren't negotiable, I had a guest who left a glowing review but accidentally gave a 1 star rating. Despite the guest confirming to VRBO that it was an error and their intention was to give a 5 star review, VRBO refused to amend it.
So they're both a bit of a muchness, both have their quirks, and both are guest centric, however, I suspect that since the involvement of Expedia, VRBO will become more like Airbnb from a host perspective as VRBO attempts to win more of the rental business.