In the long run I doubt that an MSCI World, S&P 1200 or FTSE Global will significantly outperform the other. Thus, lower TER is what really matters. It's why I'm so tempted by Core Shares's FTSE Total World ETF. If they can pull off their targeted 0.29% TER, it will be great.
VWRL/VWRA are 0.22%.