I use CaVirtEx for all my Bitcoin trading. I initially learned about Bitcoins in August 2011. I recently bought shares in the CaVirtEx IPO through Havelock Investments. However, I own less than 1%.
I decided to invest in VirtEx because I am a C++ programmer for another company (not BTC related) and I know what it takes to get a site to the point that Virtex is. Their fees are volume based, so the more you trade the lower your fee will be. For smaller volume day trading the fees will eat into your profits a bit. I believe that Bitcoin will be around for the long haul, so the fees were not as much a factor for me. I do not day trade.
Another thing to keep in mind is that Canada is a much smaller market than the US. Mt Gox has 50 times the volume of Virtex(BitcoinCharts), but still has the same costs in developing, marketing, administering the site and remaining compliant for Canadian AML laws. This means Virtex has a smaller base to make the business viable and therefore higher fees are required.
Initially when I learned about Bitcoin I researched about using Mt Gox and Virtex. I found it is MUCH harder for me (as a Canadian) to get money into Mt Gox. Thus I decided to become a verified user on Virtex. I have had nothing but positive customer experiences with Virtex since the beginning and that is important to me for my investments and my hard-earned money.
Percentage fees are the way many businesses operate. Does it require a waiter any more effort to bring a plate of pasta VS a plate with fillet mignon? The cost of the tip is related to the price of the food, so the waiter serving the mignon gets a higher amount of tip. Most investment houses also charge fees based on a percentage of money invested.
If you think that the fees are too high, then that is an incentive to start a new exchange and charge based on a flat rate. Be prepared for hundreds of hours in programming, design and implementation. Your system cannot crash and lose transactions. Once you realize all the effort that goes into such a website, I think you will want to be adequately compensated for your efforts. Unfortunately in Canada because of the smaller market that means somewhat higher fees.
As a customer I do not mind paying for good service and I also like to support Canadian companies when possible. I have also learned over the years that saving a few bucks is sometimes not worth the hassle of dealing with inadequacies afterwards. You get what you pay for.