Some reasons to stay in Canada:
* Your spouse will not be able to work on your visa (TN / H1B)
* "Full insurance coverage" does not mean for your spouse. Be prepared to pay for a delivery if you want to have children
* Your child will have much higher post-secondary student loans
* Crime, Firearms et al.
IMO coming to SV is a young/single person's game (hence braindrain from grads). But a bad idea for established people or people who want a family / social safety.