score:3
You have to shop around. Royal Bank had the best rate last time I had to change a relatively large amount and wire transfer it, most of the other banks were clustered together, and significantly worse.
The actual amount charged on top of the interbank rate should be around 2-3%, not 5.5%. The spread (buy-sell) might be 5.5, because you're looking at two exchanges.
If you just want money in a hurry (1% of $600 is only $6, after all), you can go to certain (there's only a few) CIBC ATMs 24/7 and withdraw US dollars cash using your ATM card.
I don't think Paypal has anything useful to offer.
An even better option than the other two is to go to one of the South Asian money transfer shops. There's one near Pearson airport that has good rates. Chinatown places are a bit better than banks.