I'm looking for an expresscard 34 - 2x Esata port adaptor for my Macbook Pro 17" 2.53 or 2.66Ghz (not got it yet, just upgrading!)

Reading around a little I'm getting conflicting information regarding compatibility issues with Snow Leopard and the Sonnet ones:

Sonnet Technology Tempo-e SATAII Express 34 Card Slot 2 port with Multiplier - up to 10 external drives: Amazon.co.uk: Computers & Accessories

User comment:
"Causes crashes on OX X 10.6 Snow Leopard. Not sure if this is due to the disk drive I am using or the host - either way it's very frustrating. The vendor site acknowledges that there is an issue, but seems to imply that this will not be fixed. "

Sonnet - Tempo SATA ExpressCard/34: 2-Port Serial ATA Host Controller; Compatible in MacBook Pro and Windows Laptops With ExpressCard Slot

"- Mac OS X(2) Version 10.3+
- Snow Leopard compatible"

Newegg.com - SoNNeT Tempo SATA ExpressCard/34 Model TSATAII-E342P

"-Mac OS X Version 10.5.x, 10.4, or 10.3
-Temporarily not recommended for Mac systems with greater than 2GB of memory"

I'd rather buy this model as I have read elsewhere that it is the fastest, but would love it if someone could reassure me that it does work, or if not, could recommend one that is reliable and fast (in that order).