If you are looking for a high performance shaft in the 50g range definately give the Diamana 53 Blue Board a try.
Mitsubishi Rayon's vertical integration advantage gives them the ability to produce a high performance, ultra light weight shaft that no other manufacturer can replicate.
The S-Trixx product line will slowly be phased out in 2006. Mitsubishi Rayon will be focusing on developing the Diamana and Bassara product lines globally.
I have hit the 2i and 3i MD Transition Club prototypes with an Aldila NV 105-S and UST iRoD-S. The club sets up very nice (square) and look very clean. It definately promotes greater workability. The feel (i.e. sound) is solid with a penatrating ball flight (similar to all Sonartec products). The distance is slightly longer than TM Rescue Mids in the same loft... so I would strongly recommend making the extra effort to hit them (to determine your yardage needs) prior to purchasing one.