Hey there. So, I did some digging this weekend and found what I thought I would find. In my opinion, XUU is the best. With over 3450 holdings, it is by far the most diversified. Keep in mind, XUU will charge you a withholding tax regardless if its held in an RRSP (which are usually exempt from the taxes.) So, the MER of 0.08 is misleading, although even with the taxes it works out to be very little.
However, there are a few other options if you're looking to venture elsewhere. Vanguards version of the S&P ETF is VFV, which essentially just holds the US listed ETF VOO.
VFV yields 2.24% while XUU yields around 1.96%.
Aside from dividends though, XUU has outperformed VFV over the last 5 years. XUU's 5 year return of 7.64% is marginally ahead of VFV's 6.70%. Management fees from both ETFs are practically negligible, but like said above you will pay withholding taxes on both.
If you'd like VFV's version of a currency hedged ETF, VSP is the alternative. Now, the Canadian dollar has been hammered as of late due to COVID. A hedged ETF would protect you from a quick recovery.
I hope this helped.