Marshall Rebuilt Engines, Whats your opinion?

I have been having issues finding a dependable used /6 motor close to me at a reasonable price, and I have been thinking of just ordering a rebuilt motor from Auto Zone. However I have never got any feedback from people that have ordered a Marshall rebuilt motor I have only heard feedback on the Surefire companies rebuilt motors.

Do any of you have an opinion on the Marshall company or can you recommend a company that produces a good 225 /6 motor or around the same price of $1,500.