It's free, and doesn't advertise getting the "Pro" membership too much.

In almost every survey I have seen asking tenants why they leave “non responsive landlord” is almost always in the top 3.

Fence encroachment is most common in that the contractor didn't read the survey correctly or the survey was inconsistent with the deed work.

Assuming you've received a survey that shows the driveway encroaching on the property you're buying and you have confirmed the neighbor did not receive and record a specific easement for the encroachment and the contract for your purchase of the property does not provide you're buying subject to the encroachment, I'd probably ask the seller how (s)he intends on resolving the problem.

Once my annual membership expires w/ them, I'm definitely going to purchase MPP. 

Now once you already have the management company in place and I know I'm usually having to give up control...but is it crazy to do sort of quality assurance survey to the tenants every few months to make sure the tenants are happy not only with the unit and property but with the management in place to make sure their needs are being taken care of?

Prosource is a showroom only setup where you look at samples and order...you'll likely need to create a membership with them and definitely have to wait on product delivery.

Here are a couple of 72 percent (renter as pet owner) cites, and it looks like another organization provided that survey, Apartments.com.

It's the equivalent of saying you are going to drop your Amazon prime membership, Amazon won't be filing for bankruptcy, anytime soon as a result.

Find one that can be custom to your needs, has flexible pricing, no long-term, high-cost memberships and excellent customer services to determine how to best market to your leads.