I have bought many BMWs two of which have been from Calgary BMW. I always buy used vehicles coming off lease with low mileage but for which the warranty has run out. For service I take my cars to an independent mechanic specializing in German cars "from bugs to Benz" as this dealer (as expected) charges top dollar for repairs. This review is of the BUYING EXPERIENCE ONLY. Read enough of these reviews and differences of opinion often come down to the individual they dealt with.
A few years ago there was a car at Calgary BMW I was interested in but the salesman didn't seem very interested in selling it to me. I made an offer a couple of thousand less than asking price he said he wouldn't entertain anything less than asking price. I went to BMW Gallery the same afternoon and bought a different model.
I can however highly recommend Dan Gulin at Calgary BMW if you are looking to buy a car. He's honest, straightforward to deal with and doesn't play games. Make a reasonable offer and it will be a pleasant buying experience.