Correct. The XL version of the Letus does away with using the standard 20x as a relay lens and hardmounts to the body. I have an XL2 and have yet to use this set-up as I'm waiting for the "extreme" version to come out.
It's not for sale any more. But I hope they are working on a new sample. Since the last one didn't do wonders and lost around 4 stops of light (the primary reason that I don't care for using a adapter). But as soon it shows I'm very interested. If you seek more info about the old one, here is a link: http://dvinfo.net/conf/showthread.php?t=80064