Be aware that if you hold a US domiciled ETF in a Swiss broker, it is important that your Swiss broker is a “qualified investor” (QI). Otherwise, you lose 15% of dividends. Most notably, PostFinance is not a QI!
A better alternative instead could be TradeDirect. They are a QI and they are backed by BVC cantonal bank, which has pretty good AA credit rating (be also aware that SwissQuote does not even have a credit rating!). Last time I checked TradeDirect (not sure if numbers are still valid), the maximum annual custody fee was 108CHF, the fee to move stocks in/out was 0/150CHF.
So, if you are looking for a very trustworthy Swiss broker at a reasonable cost, TradeDirect is a very interesting option, especially for high net worth. Make sure that you buy on IB and then transfer stocks to TradeDirect, in order to avoid TradeDirect transaction fees.
More details: W-8BEN on your own & 30% withhold - #18 by Frank