As @Tim Joyce stated it has some protections for you but you need to weight those vs the protection you get from a good personal umbrella policy. 

But I listen to their podcasts almosts every day.Their basic principles seem to be pretty good - 3bdrm, 2bath homesin middle class price range.What I think you'll gain though is well worth the annual membership fee - networking opportunities, special pricing from approved vendors, etc.And the free phone calls are worth their weight in gold for an investor starting out.

For me, it adds weight to the answer that is being formulated in the post.

The appraiser can place all emphasis on just one approach to value, or give weight to both. 

When I lose weight and get hair transplants I'll post my pic, until than I'll have Atticus Finch "represent".

He was working on putting up a railing going to the second floor before I paid him, but when I visited the house afterwards it was ripped out of the wall by its own weight because it was only screwed in on one end. 

From there draw a list of pros and cons and put a weight to each. 

How would you weight these criteria?

But, don't attribute too much weight to the whole 2% thing...consider it a wish list goal...

Either way, you should examine the market to determine what you should offer and put less weight on the list price.