Hi Watchcaddy,
I'm currently using a Hyperdrive HD80. A few people I work with have researched this and have found it to be one of the fastest in terms of downloading CF cards. To give you an idea, I can download my 8gig Sandisk Ultra II with 3.5 gigs of photos onto this device in approximately 4.5 minutes. Thats pretty quick in terms of downloading. I find the biggest complaint with other devices is that the cards take too long to download and the device goes through batteries really quick. The HD80 claims that it can download approx 80Gigs of data on a single charge. The unit I bought was the enclosure, and I bought the hard drive separately locally (80Gig notebook drive). I've only had this for a month, and it really works great. I shoot weddings and I download my cards to this when my CF cards fill up. And, as a backup, I also download to my MacBook Pro. Here's a link to the site where I bought it:
http://hyperdrive.com/shop/index.php
I really mean it when I say that this thing downloads fast! I haven't come across anything this fast. Only downside is that the unit cannot display the photos you take.
Hope this helps. Email me if you have any more questions.