I ordered this so my husband and I could learn a little Armenian (I am of Armenian descent). I have other Armenian language tools, such as the VocabuLearn cassettes, a textbook, and Samuelian's transliteration dictionary, and they are all helpful in their own way, but in terms of amount of progress for time spent, Pimsleur beats them all.
If you have ever listened to the Pimsleur compact programs for other languages, you will be familiar with the structure. I have listened to the first lesson of two other languages, and the Western Armenian one is no different. They start out by teaching you how to ask someone if she understands Armenian (or whatever language the tapes are for), and by the end of the first lesson, you can understand and participate in a brief conversation that centers around that. Each subsequent lesson builds on that first lesson, teaching you more words and phrases. The lessons are in both English and Armenian, just as an FYI. This is not done in an immersion method.
The way that Pimsleur handles pronunciation is also very helpful, especially for individuals who are not used to hearing Armenian. Some of the words are very long, and can sound very confusing. Pimsleur walks you through the pronunciation of each word, starting with the final syllable and working backwards. My husband, who has pretty crappy pronunciation (since he didn't learn how to make the "gh" and "kh" sounds), has been doing surprisingly well with this method. I still have to help him out, but overall, it is as good as can be expected without an actual person telling you what you are doing wrong, although the lessons do usually address common mistakes.
Pimsleur also sneaks in grammar lessons, so you gradually figure out some of the grammar constructs. Some people catch on to this more easily than others, but the course does make an effort to teach you.
Now the bad: The Pimsleur course doesn't come with any written materials, so if you are confused about a particular sound ("Is that a "t" sound, or a "ts" sound?"), there is nothing to check to make sure.
Also, the Pimsleur courses (in general, not just the Armenian one) seem to be geared towards people travelling, rather than learning a heritage language to converse with relatives. The actual words and phrases that it teaches may not be helpful to you if you are learning it to converse with family. When will you really need to ask them if they understand English, or tell them that you are American?
Overall, though, this is the most user-friendly Western Armenian audio language tool that I have found, and I would still highly recommend it to anyone trying to learn the language.