Yes, I have two MKS 5mm tensioners on my Pista, and I can hardly see them.
They work great.
I have two MKS 8mm tensioners on my Surly Karate Monkey.
When and if you intall MKS tensioners, the flat washer portion goes between the hub and the dropouts, and the MKS logo on the tensioner barrels goes outboard, away from the center of the bike; outboard left on the left tensioner and outboard right on the right tensioner.
Start out with a chain a little too long, and shorten it a link if necessary.
With a little experimentation, you can get the hex nut inside the barrel flush with the barrel.
Experiment, and start with a chain one link too long.
It works well, but I didn't like it aesthetically.
The MKS tensioners disappear in plain view, whereas, to me, the Surly Tugg-Nutts just shout "look at me."
Yeah, it worked beautifully but didnt match that in the looks department. Its also a lot bigger than MKS option but you do get a beer opener, which is useless if you dont drink, like me. However, at the time I wanted to be riding asap instead of worrying about my Langsters aesthetics.
Edit: Ken beat me to the MKS part of my reply and covered all the bases.