Thinking about tethering my 8530 - how fast will it be?

For the sake of trying to save on my monthly home phone bill that includes high-speed Internet, I was thinking of setting up my BB as a modem by tethering the device. However, I am reading that connection speed is not dramatically faster than the days of ancient dial-up - in fact, when configuring for the modem, I actually use the dial-ups settings.

I need some advice and input on this, will I have a very slow connection if I use my 8530 as a modem? The data plan upgrade thing is no big deal as I can enhance from 500MB/month to 1GB but I do not want to be plagued by deathly slow speeds....

I am currently using Bell Aliant as my cell phone carrier up here in the Great White North.