Both of those bin designs are more similar than different and retail for around $100.
If you haven't vermicomposted before, I'd suggest a more simple start-up solution.

Foolproof vermicomposting comes from your understanding and knowledge, not an expensive bin.

If you're handy, you might even make a system every bit as good... or better.

Here is a link that might be useful: OSCR Jr.

mymet...Abbeysdad makes a a good suggestion and a very good point about "foolproof" vermicomposting.
I have many COW's and have worked with the Worm Factory. I do not like the Worm Factory's lid. It is not fitted like the COW's.
I also have many bins that I made out of various materials. One that works very well is the 10 gallon rubbermaid roughneck (found at Lowes). If you are just starting out this could very well be the best way. Starting small and learning how a bin works for you, specifically, are important factors to your success.

i have the worm factory, with only 3 trays. i'm really happy with it.

Try doing a search for COW and "worm factory" on this site. There has been much discussion over time of both systems, how they work, and how they compare to other (much cheaper) setups.