First I'd like to say I agree with what appears to be the consensus on this product: a bit overpriced, but does what it claims. The Rosetta Stone language philosophy is: Language immersion through learning + feedback through a well-rounded (and fun) program which reinforces comprehension & pronunciation (including accents).
ROSETTA STONE APPROACH:
I am a far cry from being a language expert, but I have used other language programs (and other Rosetta Stone program), and I believe the have a very solid product.
Many users have complained about the "immersion" approach - so here's my quick 2 cents on that: There are several language theories, and I tend to agree with immersion. I have some academic reasons for this (I've studied Chomsky, linguistics, semiotics, etc, in graduate school), but for me the proof is in the pudding when I watch my 1-year old child acquire cognitive tasks like language. She obviously does not use flash cards or try to memorize words one at a time - she is immersed in the language every day (hearing it, seeing it, trying it out, reacting to our feedback) and picks it up like a champ.
The apprehension from Rosetta Stone users (I believe) is that Japanese is *so* foreign from the Romance Languages (English, Spanish, French, etc) and there is NO English (zero, as far as I've seen) in the program. So if this makes you apprehensive, and/or if this isn't your learning style (hey - everybody learns differently), then I would suggest avoiding all immersion-based softwares (not just Rosetta - that includes most of the top companies). But for me, this is my preference.
The program has 3 parts: The course/software itself, the "studio" (get 9 months with your license - interact with native speakers), and the Rosetta "world" (also 9 months - play games, etc). The three together (theoretically) provide a well-rounded language experience. However, please note that you are paying for the extras - the software itself is fairly similar to much less expensive alternatives (like the Instant Immersion brand).
There were some problems with the software (running on a new Windows 7 laptop). It was a bit clunky, runs slow, and even crashed my system a few times.
The larger issue for me (as with all Rosetta Stone products) is the licensing. You are only allowed to load the program twice (theoretically, one copy on your desktop and one on your laptop). But if you have a crash, a stolen laptop, if you need to reinstall due to Windows errors, then you are basically up the creek - you have to buy another copy.
In my opinion this severely limits the use of your program (and as one user put it, you never really "own" it). Another user encouraged me to look at it another way: This is a course (like a college course) - and you should spend 9 months with it and then never need it again. Learning a language is not really like an operating system or photo editing software, where you basically use the same functions every day for several years - you progress through the program then you're done.
All I can say is, the licensing restrictions really make me feel uncomfortable. At heart, I really believe if I buy a product (and have the serial number), I should have unrestricted personal use of the product. I should be able to transfer ownership (put it on my wife's computer when I'm done with it), resell it, load it onto my next computer, etc. And this raises another limitation - I can't use it on my netbook (which I travel with) because I've already used my 2 installs, but also because the CD-Rom has to be in place to use it. So if you plan to use it while traveling, or even at work, for example, you can't unless you also carry around the discs.
Some users have reported that the early levels don't really teach you relevant phrases, and I tend to agree with that.
Also, the headset is cheap - not a big deal in my book, but it really makes me curious why Rosetta Stone would sell a top shelf program and include a dollar store headset.
This product is NOT for you if: (a) Any of the issues I mention give you pause, or (b) you're wanting to learn casually - and not serious about jumping right into the program. Also, if you're looking for an effective yet less expensive alternative, they're out there.
You won't find any other out-of-the-box product as comprehensive as Rosetta Stone, but you can definitely piece together your own learning program (i.e., Instant Immersion for $10, then Google for language free games, audible feedback, etc). Other reviewers have mentioned several other options.
However, if the cost doesn't bother you, & if you're OK with buying another copy should your laptop get stolen or computer crashes, then I say go for it! I truly give it 4.5 - 5 stars based on its merits.