Right. Negligible.
Just so the users know EXACTLY what they are trading for [more-or-less] speed:
Render Method: Final = three transparency events. If you present the renderer with four events, the last one is rendered as opaque. Several Archicad windows and doors have enough glass to cause this problem if rendered partly open - the overlap is solid. [BTW: Best Method = 40 transparency events: a whole heap of unnecessary calculating. A clever user could go into the LightWorks settings using one of those preference setting utilities and turn it down to 6 or 8. A fair compromise…]
Antialiasing: one step down from Best = an antialiasing method using both processors rather than only one since that "Best" method is not optimized. The downside of this is in a fly-through where complex texture mapped surfaces are seen, the disturbing and client-alienating effect "texture squirm" happens. A thousand worms gyrate on your granite counter.
You'll know it when you see it.
Dwight Atkinson