Purchased the full version of Spyglass a while back and I have been underwhelmed.
SEO Spyglass basically does what it says ... but you're not going to be surprised by great results. Of course, it is just reporting information that is readily available from the search engines. I thought it might be worthwhile to have it gather everything into one place, but I was wrong.
*) It is very basic. You can put in keywords or a URL and have the tool examine it.
*) I found that the results were off-topic. That is, not what relevant for what I wanted. The real disadvantage is that you can't re-direct/pare down the results. You know how you use advanced search techniques in search engines to find what you really want? You can't do that with SEO Spyglass ... which means you're back to the early days of the internet. Searching through a ton of results that you don't care about.
*) It just spits out a bunch of data. It's up to you to make sense of it and get results. If you're a webmaster looking for an automated way to gather a bunch of stats, I guess it would be OK. If you really want a tool to help you improve your search engine ranking, look elsewhere.
*) It is sloooow. I've let it run overnight before and it never finished.
In short, the interface is basic, but getting what you want out of it is very difficult. If you want to spend a lot of time getting up to speed and analyzing data, maybe you'll like this software.
Anyway, they have a free trial that you should definitely try first. I wish I would have ... then I wouldn't have purchased the full version. There are better services out there.