This is an interesting note. So what if I just go buy VTI directly on the NYSE and hold that in my RRSP? Am I having my cake and eating it too?
Well you have to deal with the FOREX costs in that case, but you avoid the 15% witholding tax on your ~2% dividends - so that's 0.3% you'd save each year vs. holding VUN. You'll have to work out if the FOREX costs are worth it depending on your specific situation.
One option is to buy VUN until you have a sufficiently large amount, then do a 'Norbert's Gambit' to switch CAD to USD.
It's not worth doing forex on small amounts, generally, but 0.3% on $50k? Worth doing, I think.
That's somewhere like Questrade, where buying ETFs is free, and selling costs $5-10.
With Interactive Brokers, forex costs a couple of dollars, so it's worth doing as you go.
With CIBC Investor's Edge, in a registered account, they basically don't charge forex as you can't hold USD; so when you buy US stuff, the conversion is done at spot.
I know some brokers don't even allow you to do Norbert's Gambit. You can, of course, do the forex elsewhere - for example, you can get USD into a Canadian-based RBC savings account, and then do an EFT from that account into an RRSP already in US funds.