Hi, thanks for your post. 0) Only iGuidance 4 has TTS right now. TTS is not available on TT6, OCN6, and Garmin Mobile XT. 1) In terms of graphics, it is very subjective but IMHO, OCN6 has better 3D view and road edges is smallest among all iGuidance 4, TomTom 6 and Garmin Mobile XT. The smaller road...