Difference in Class 4 vs Class 6 microSDHC cards for the Impression?

Hey everyone. My wife and I just bought a few 4GB microSDHC cards that are class 4. I was wondering if Class 6 was significantly faster or different for the Impression, such as saving media (pictures, movies, etc) or viewing them?

I understand that Class 6 cards are faster in transferring files--so I got the idea that they were faster if I was transferring files from the card (phone) to the computer, but not sure if there was a lot of difference for in-phone use.

Thanks.

Ah, I see. Thanks for the correction. Does that mean if I take pictures and save them into the card memory--they will be considerably faster for Class 6? Will there be less "saving time" in the Impression?

I guess I'm trying to determine whether Class 6 is will make the experience any smoother for this phone.