Piston pilots transitioning to the Phenom (and other turbine aircraft) are surprised to see that the Roll Indicator operates in an opposite manner for the two aircraft types.  This is true even for the Garmin 1000.  For piston aircraft, the Garmin 1000 has the upward-pointing arrow acting as if it were attached to the top of the vertical stabilizer; it moves as the aircraft moves.  The Embraer Prodigy display, on the other hand, uses the upward pointing arrow as a "Sky Pointer" always pointing to the vertical.

Don't believe it?  Here are two screen shots of the Garmin 1000 PFD, one for pistons and the other the Embraer Phenom PFD.

Piston Aircraft PFD Source: IFR magazine, Feb 2010, p 14

Phenom Prodigy 100 PFD Source: Prodigy Pilot's Guide, Rev. A, p 278

Note that on both PFDs the upward-pointing arrow is to the right of the downward-pointing arrow on top.  Unfortunately, these depictions have two opposite meanings.  For the piston aircraft, the wings are banked to the right, and for the Phenom the wings are banked left.  This is more than confusing.  In a high-stress situation it would be easy for the transitioning pilot to correct in the wrong direction, steepening the bank rather than leveling the wings.

Pilots are trained to use these arrows, or triangles, to maintain a specific bank angle or roll the wings level.  As IFR magazine (Feb, 2010, page 12) instructs "For roll, the top of the display often shows two triangles with points that touch at true zero bank.  The display is incredibly sensitive so the slightest bank shows instantly.  Unless you're supposed to be turning, these points should be perfectly matched.  It's the first point of the PFD I look - and the first thing I correct - when returning to the flight instruments after looking away for some other cockpit task."  Unfortunately, how you react in a jet is exactly opposite as to how you were trained in a piston aircraft.  So be careful.