The ETF tracks the index, so the question are:
1) You know the index, you think it’s diversified and has had good performance?
2) What it the TER, meaning the price you pay per year (included in the price of the ETF)? Higher or lower than the average of the same index ETFs and in comparison to similar indexes ETFs?
3) You trust the company (Vanguard in this case)?
That said, imo I think if you like the index, most probably it’s a good fund, Vanguard is well trusted and with low TER for what I know.