@Sean Dolan Like I mentioned in a previous reply, I am an Investor Carrot user for 4 years now. When I started using IC I also setup my own website, hired an SEO expert to help me out with it and hired a content writer to publish articles. For investor carrot I used their content package to publish articles twice a month and did some citations.
For about 18 months I had both sites running.
By month 18...
my custom site ranked #2 for my main keyword and the Investor Carrot Ranked #1.
my custom site was getting less visits per month...but not by much
The Investor Carrot site was converting visitors to leads at a 5 to 1 clip
I get the point of Ownership vs Renting and that was one of the negatives when I was deciding to go with Investor Carrot or build my own site. But what it came down to was Time and Money.
I could...
spend 100's of hours building my own site, learning the techniques and testing out designs.
hiring people to do SEO, Content writing and/or web design (which is NOT cheap)
or I could....
Rent a website (Carrot or Lead Propeller) for $50/mo that has Content already done for you, on site SEO built in and a research, tested and done for you design.
You still have to do off site SEO but that is becoming less and less important in google's eyes. it's all about the Content these days.
My custom website cost me over ~$4000 after 18 months from hiring out the SEO and Content, buying a template and some plugins (Gravity Forms), while over the same time Carrot cost me $900 (that was actually for 3 sites as well Seller, buyer and Company).
To get to your point about Renting Vs Buying. I fully understand that the core Carrot content that is on my site now is not "mine". It will go away if I ever decide to cancel, which is fine because as long as I am an Investor I don't plan on cancelling. If they go out of business then the content is mine to transfer to my own site (I asked).
There may be a few other negatives to "renting" your site like not being able to sell it or being able to install custom wordpress plugins, but that is okay and for me not a deal breaker.
That has been my experience and my 2 cents regarding the subject of Owner/Renting websites.