SilkTest Question:

It really depends on what you are testing. For complex web sites (pages not static, multiple browser windows, JavaScript), I would say SilkTest works much better.
In general, Visual Test is new to the web browser game. If it is a Win32 app that you are testing, VT is *much* faster than Silk and the code compiles down to a binary file that can easily be put on diffrent test systems. This is a *big* plus for Visual Test.
SilkTest will make the declaration file for you, so this saves allot of time. In VT, you have to make the declarations yourself, but if the product isn't huge, this isn't a big deal.
SilkTest also is great a capturing text on a page (either web or Win32 based). VT, last I checked, lacked this function. It is a useful function for verification.
SilkTest also has a nice verification function that it makes (a few keystokes and it's done). Real easy to change some of the hardcoded data here with data from a text file or other place. Nice for doing report verification where the layout is the same, but the data is diffrent.
Cost is another big issue. SilkTest is low in price, Silk quite high.
So, again, it depends on your needs, what and how you will be testing it.