Which broker is cheaper for SG is purely a maths problem. For some investors, philips is cheaper, some IBKR is cheaper, and for some, FSM is even cheaper.
user cclee created a spreadsheet for which broker is cheaper for foreign shares, maybe he can expand the spreadsheet to which broker is cheaper for SG shares, to help those who can't do the maths
That's the thing, it's really different depending on the actual circumstances -- some people for whatever reason just want to buy one big sum and don't plan to continue buying, some already got enough AUM to meet SC Priority, some are on track to IBKR's USD 100k soon, some have trade sizes where FSMOne flat $10 for >Silver clients matters, some care about CDP, some want to diversify across brokers... I actually would expect that just buying SG shares only is thoroughly covered by all those comparison blog posts or whatever though.
Might be more interesting to see when plonking both global and local equity into IBKR SG makes sense, and if it makes sense to throw in A35/MBH into that instead of FSMOne RSP.
I saw in your Rich by Retirement book that the Internal Revenue Service—the US tax authority—imposes very strict rules on US taxpayers who invest in stocks or ETFs that are listed outside the USA. For myself, I am due to relocate to the US in the near future for my employment and I would expect to be working in the US for a number of years once the relocation happens. In that case, would it still make sense for me to buy the London-listed ETFs such as IWDA/VWRA right now? Otherwise, what would be appropriate to buy? For my retirement country, it is not something that I have decided as of yet.
I am not a tax lawyer, etc etc, but the last time I looked at this I concluded that the more kiasu thing would be to liquidate as much of my investments as I can before even stepping foot into the U.S. in the year (because it seems that if you meet the substantial presence test for the calendar year, tax residency start from the first day in the year you were present -- unless you start late enough in the year and don't opt in?) to get rid of stuff that runs afoul of PFIC rules, and to reset cost basis (keeping in mind wash-sale rules if rebuying PFIC-compatible stuff), and maybe also do all the FATCA/CRS tax residency change notifications and see if anyone abruptly requires me to take my custom elsewhere. Super annoying just to figure out what's necessary.
There -- now that I've said something possibly horrifyingly wrong, hopefully someone is typing furiously now to explain exactly how I'm wrong
(I do recommend checking out Alliant Credit Union after you move! They're fairly nice to deal with.)
but would like to know. I suspect not, as IB is more like SC, but will be good if it does! 
