Camcorders: DOES IT MATTER the type of SDHC card used for HD Camcorders?

DOES IT MATTER the type of SDHC card used for HD Camcorders?

I've recently purchased the Canon Vixia HFS100 -- Absolutely Love it BTW...

That said, I'm confused over what type of SDHC card I need to maximize the quality of my pictures. I've purchased a Lexar 16 G Class 4 "FULL HD VIDEO CARD" for $95 canadian ($37 rebate coming back). From what I've seen in the last week - the card works just fine. BUT...I've noticed on the card specs that it reads at a maximum 15 MBPS. Now, my Canon records at a bit rate of 24 MBPS in its hightest quality (MXP). Does this mean I'm sacrificing quality of my videos with this SDHC card? Or are these numbers apples vs. oranges. I'm a relatively experienced camera operator - but digitally I'm a bit of a newbie.

I'd also like to know if I need to spend big bucks on 'brand name' cards, or if the cheaper alternatives will do just as good a job.

Appreciate any advice or feedback.
Snackage