how many minutes and data do you plan to use during your US visit? If only for emergencies or one short call a month, roaming charges may be workable. US passes are great for moderate usage. Yes SIM card swaps are better for high usage customers.
US sim card swaps means friends cannot reach you by your Telus number.
how do you plan to acquire you US card? Not all airports and hotels can sell you a SIM card. Look for retailers who are willing to install and test the SIM card prior to you leaving the store. I hate those stores that sends you back to your hotel and you have to figure out how to configure the card yourself.
research coverage.... like Canada, different US carriers will have different coverage in different states? Discount providers have poor coverage and often offer no coverage indoors behind concreate structures.