Tshadow gave a more complete answer but I did want to clarify the reason for my post.

My attorney tried to get me to sign a C&R even though the MSA was done totally incorrectly. If I had not got a copy to look at myself, I would not have known it was wrong. So it good to know what to look for in an estimate.

The attorney was trying to convince me it would go through Medicare. (He later admitted that I was right to suspect it would not go through.)

There are some unreputable firms doing MSA estimates. I've seen a $25,000 estimate for a million dollar injury.