This used to be my friendly neighborhood costco and I still visit it when I'm headed in or out of Brampton and a costco stop is needed. I find that their selection is a little different from my usual costco (heartland) and doesn't carry all of the things I usually buy. It is however a much more open and spacious location. Brampton has a smaller population than Mississauga so it makes sense. As with any costco though, go during a weekday if you can to avoid the craziness.
The cashiers are quick and courteous and the people who check your cart at the exit actually watched my cart so I could pop to the bathroom quickly.
Costco is always worth the price of the membership - the prices on bulk stuff can be awesome, but slightly annoying how someone always tries to sell me on the executive membership.
The parking lot is a bit of a madhouse but it's right off the highway so it's definitely a convenient location to get to. I am pretty sure it's the only costco in Brampton.