Motorized Mash stiring in your Tun.

Has anyone tried using a motorized mash stirrer in your mash tun?
If so has it made any improvements in your efficiency?
How did you go about setting it up?

I am thinking of working something out, just curious if anyone has tried it.

I have no experience with it but you did remind me of an article in this months BREW Your Own magazine. Titled Mash Mixer Efficiency in the mr. wizard section on page 15. Might be what your looking for. I'll give it a read and check back in later.

I read that article too.  The new issue has more testimonial about how great it is and how it massively jumped the efficiency. 
Seems like a lot of work and expense for a homebrewer though.
With the increased efficiency, you will end up adjusting your recipe a bit to get what you make now. 
The work and expense is going to essentially save you a buck or two in grain in a recipe.

Of course in this hobby, like most, it doesn't have to make sense.  We do a lot of stuff just because we want to.
I'm planning on building a heat exchange for my mash tun.  It will (if I do it right ) allow me to be way more consistent with my brewing, but it's hardly an needed upgrade.

If you have arms, there is a simple device that can be custom made that is very effective at stirring mash. It is called a mash paddle. If you have a gym membership you should be able to work up your endurance to stirring your mash every 10-15 minutes. Slide the paddle to the bottom then raise it back up 4" then stir. You won't disturb the bottom filter layer of the mash.

Every system has an average efficiency. It is effected by many factors. Old grain, different base malts, mash time, and draining your mash tun into your boil kettle which is usually the main culprit. My mash tun drain is 60 min for a PBV of 18 gallons. If I go 45 min my eff % will be off. What ever time you settle on stick with it or your eff% will be all over. If your efficiency is between 70-85 you don't have a problem. It is a number not worth chasing, focus on repeatability of your technique, and not brewing gadgets trying to reinvent the wheel. Most all of us don't brew in a laboratory. Keep it real!