Memory Stick Pro Duo Cards

[CariB]

I recently purchased the Sony W150. I currently have a Sony Memory Stick [MS] Pro Duo Mark 2, but would like to purchase an extra memory card. A friend recommended I purchase a 4 GB or 8 GB Sandisk Extreme III MS Pro Duo .

However, I have been wondering if I will notice much difference in read/write speeds with the various MS Pro Duo cards offered by Sandisk and by Sony, specifically:

1. Sony MS Pro Duo [Mark 2]
2. Sandisk Extreme III MS Pro Duo
3. Sandisk Ultra II MS Pro Duo
4. Sandisk MS Pro Duo

Thoughts? Recommendations?

Thanks in advance!