I sympathize with EB's grievance. Things can be a little messy. But more info is good, even if it requires hitting the search button (however, some people like me have ten broken fingers and can't click search).
As for the original question...
In my opinion the best place to exchange is the Casino Montreal. They have no surcharge (unlike the exchangers on St C), and their spread is a bank's spread because it is done by a bank (bank spreads are the best). The only danger is that you will gamble while in the place, then you'll wish you had went to the exchangers on St C. My routine is to drive up to the valet parking, which is free and quicker than the self or bus transit parking, and drop off my car there. I exchange, and then tell the valet I lost all my money to the casino ($0 tip, the cheap bastard I am). Most of them understand.
Bank spreads are about $1.50 Ca, meaning if the currency is going for 132 Ca for 100 Am on the FOREX, you will get about $130.50 Ca for 100 American. Don't let the St. C boards fool you. They seem to have better spreads than the bank spreads (about .75 to 1.25 cents better), but they add on a fee, usually $2.50. But this means that if you exchange about $1000 Am or more, you would be best off exchanging it all with one St. C exchanger in one transaction. Can anyone with better info recommend a better spread?
The problem with many banks is that they will require an account or else they'll charge a fee, although I've found a few that will exchange for the spread only. Also banks close early, whereas CM is open 24 hr.
If you are really really stuck, then try the ATM, but you will be hit with fees usually.
If you insist on exchanging money in a strip club (stupid), my observation is that the best strip club exchange is at Club Downtown, usually about 10 whole points better than other strip clubs.
If you really wanna be an ass...some restaurants in DT Montreal will exchange money and they won't be up to par on the info. Most people roughly think that the exchange is 1.5 to 1 (historically correct). If I eat, I always ask the waiter if I can exchange money, and a few will tell me they tell me that they give 1.5 to 1 (or some out of date above market figure). If so, and you can live with yourself, exchange the maximum amount. I once exchanged 500 American into 750 Canadian, while the going rate was 137 FOREX (meaning I got overpaid about 65 Ca). Most limit to about 20-100 or so dollars. I once even exchanged at the burger king on St C and the stupid manager gave me 25 Ca for 10 Am, minus the order.
Finally...DO NOT EXCHANGE at the duty free store; they are a rip off. On my first visit to Montreal, before I knew anything, my friend told me this was the best place to exchange because they won't tax your exchange...that advice was so wrong and stupid I want to kill that guy.
For current exchange rate...and, yes, it ain't too pretty...
http://www.xe.com/ucc/