Some say the STEC 55X is the best autopilot for the Lancair turbine and
others swear that the TruTrac is the only way to go.  Any comments from
those who are flying would be appreciated

If the 55X still uses the tilted turn-coordinator gyro as its main input (like the 50), don't even consider it.  I use the 50 and have to turn it off during turbulence (even light chop).  The 50 converts vertical movement into turns, some as much as 8 degrees off course. If I make any major change to my plane it would be to install the Tru-Trak.