Fernando Midi did an awesome Ableton Link enabled DJ set, with Serato sync'd to Ableton and Figure.
In testing Serato Dj and Ableton Live Link. Sync is perfect and does not take away the freedom to use the Turntables however you want.
2 X Vestax PDX 3000 Mk2 - Turntables
Pioneer DJM - S9 - Mixer
Native Instruments Maschine Jam with Control Script for Ableton. (Perfect!! )
A Macbook Air 11" corei5 1.6Ghz, 4 Giga of RAM 1600 MHz, SSD 128GB.