Two things make it much better then the old Parallel ATA.
1. Smaller data cables. Gone are the wide gray cables. SATA uses very thin wires, making cable management much easier.
2. Higher data rates. Currently SATA is 150Mb/s but the technology allows for increased rates, 300Mb/s and up to 600Mb/s in the future. This is necessary because currently the 133Mb/s maximum of PATA is becoming a limitation.
In short, if you are making a new build, definetly get SATA. It's worth it.
