We use VBCE too but mainly for major currencies and for the convenience.
Charlie's Currency Exchange on Granville has better rates for the more common currencies. However, they interestingly only deal in cash (no debit).
[There are also a lot of sketchy currency exchanges in Richmond with good rates. There's been some interesting articles in the paper about money being transferred from China to Vancouver via these currency exchanges to buy real estate.]

We generally find exchanging for hard currency in Vancouver before a trip particularly not worth it if we're going somewhere like Vietnam and the currency falls under the "exotic" category since the spreads are pretty big.