One thing I found was that VRBO is much more amenable to price negotiation than airbnb. You can easily email a whole bunch of property owners with an offer, where as airbnb isn't really set up to do that. I've been able to get beautiful homes for less than half the price listed in VRBO during the offseason (summer in Central America). I've also been flatly turned down by everyone when trying to negotiate during the regular season, so this seems to only work if you're in a time of really low occupancy.
As for reliability, I've only had one bad deposit return experience in 10 years of VRBO rentals all over Europe and Central America, although keep in mind they don't have much insight or control over an outright attempt to scam. I feel like you take a little more risk with them over airbnb, but in exchange can get better deals.