Or should I work with a real estate agent and find a property and then hope that it rents out amongst all the other competitors?  

Would competitors bid as high as (or very close to) the AV?  

In other words, its all cyclical and the only way a downturn would be a complete disaster is if you have not positioned your current portfolio to keep generating income even through a storm and if you are not managing your assets in order to buy good, cheap deals during the downturn while unprepared competitors are caught off guard.

I can't tell you how many times sellers have worked with me, over competitors who hawk the same deals, simply because I approach negotiations truly with the seller's interest in mind.

Bottomline, on the informal line, I agreed we will not actively market to his competitors, but if an agent brings one, or we are approached independently, we will consider it. 

At one time I thought it was the way to go and then I heard that those sales sites are now crowded with many competitors I was turned off.  

So it may be a self perpetuating cycle of only using one because that is the one that gets you the most bookings.If people are just getting started it is good to set your price below your competitors to build up a few good reviews then raise rates.I can't speak to the other platforms as I only use airbnb and homesuite for 1 to 4 month typical rentals.

try to get lending club loan or from their competitor.

I know how much to charge each month, how many bookings my potential competitors have each month, etc.

I have found even competitors in this industry very supportive BUT just to make sure I would get your relationship in writing and discuss the potential conflict of interest in advance.