I have been using this for a month now, and can honestly say, while it is not perfect, it is an absolutely fantastic utility which saves time and effort in setting up new PPC campaigns (and allows you to easily see what is working and what is not working for your competitors, so you don’t have to reinvent the wheel:-)
If you do PPC for a living, and can’t make KeyWordSpy pay for itself many times over, then you are in the wrong job! (It also is fairly useful for SEO).
It is also recommended by Howie Jacobson, so you don’t just have to take my word for it!
(NB – Unless you are a *big* company, you only really need to purchase the ‘research’ option).
If you do try it out, please let me know how you got on… Thanks.