About me: I have been using Rosetta Stone (v3) Japanese for about 3 months, and am on Level 2 Unit 4. I studied Japanese with a private tutor for 6 months about two years before I started using Rosetta Stone, and I have a Japanese boyfriend. I have free access to Rosetta Stone courtesy of my school.
In short: I have enjoyed using Rosetta Stone for free, and finding the motivation to do daily Rosetta Stone sessions is very easy. However, the longer I spend learning with Rosetta Stone, the more concerned I am that I am not actually learning Japanese, I am just learning Japanese translations of English. I firmly believe that Rosetta Stone must be used with supplemental learning materials that address usage, culture, grammar and vocabulary. Given how much is missing from this language learning solution, it is definitely not worth the sticker price. If you can access it for free, though, you might find it worth your time ... or not.
- Low stress level (there is almost no challenge; it is always very easy, so you never worry that you're going to 'fail')
- Option to switch between romaji, kana, kanji, and kanji with furigana at any time
- Professional photography (when the models don't look corny, the photos are almost always extremely beautiful)
- Polished software (relatively bug-free, but not without typos or speech recognition difficulties)
- Intuitive interface (for me, but not for everybody)
- Copy-and-paste from other languages: Rosetta Stone takes a copy-and-paste method to producing their software for different languages. You end up learning a lot of vocabulary that is American or Western, like salad, sandwich and bed, but not sushi, unagi or futon.
- No emphasis on special features of Japanese: This is a result of the copy-and-paste method. Japanese is quite different from English and the Romance languages, but Rosetta Stone almost completely fails to acknowledge these differences. One specific example: Japanese months are numbered regularly using numbers, not names. So January is '1 month', September is '9 month', etc. However, Rosetta Stone insists on drilling you on the 'names' of the months, even though you learned the numbers 1-12 many units ago. Moreover, Japanese days of the month are numbered using two separate numbering schemes (native and Chinese), but there is no attempt to teach you the days of month systematically. Instead you find out incidentally along the way that some days of the month are not constructed as you expect. There are many other examples: style (levels of politeness and formality), adjective conjugation, etc.
- Inaccurate usage: Again, a result of the copy-and-paste method. One specific example: Rosetta Stone presents 'ii deshita' as 'was good'. This is a literal translation of the English (or Romance language), but no Japanese ever says that. They say 'yokatta desu'. (It is the adjective that is given the past tense, not the auxiliary verb.) There are many other examples: putting subjects into almost every sentence (when Japanese typically omit subjects), using 'gomennasai' instead of 'sumimasen' in some contexts, no emphasis on in-group vs out-group vocabulary, etc.
- No cultural awareness: All languages are highly intertwined with culture, but the culture you see in Rosetta Stone is completely American or at most, Western. For example, when refusing an invitation, a Japanese would almost never say 'no' straight out, but present very polite excuses.
- Writing practice is rudimentary
- 'Milestone' activities at the end of the unit are too close-ended. They have a pre-written script that you must follow in order to be graded as correct; however, in a real conversation, there is always more than one way of saying something. There are many appropriate responses you could make, and while accounting for all of them is obviously impractical, there often at least two or three ways that would be common given the material already taught. The milestones would be a lot more enjoyable and realistic if the script allowed a few variations when appropriate.
Note that I do not comment at all about the 'immersion' approach taken by Rosetta Stone. It is up to you how fun/effective that approach is for you, and how much time pressure you're under. I think Rosetta Stone does a decent job at the immersion approach, but I'm no expert.
Recommendation: Do your research to find out if Rosetta Stone is worth your time or money. There are a lot of language blogs out there who have pretty negative reviews, and they go into detailed reasons as to why. In my opinion, Rosetta Stone Japanese would not work well for absolute beginners or advanced students. It would only work well for advanced beginners, those who are still beginners but who already have some Japanese learning. Japanese is a relatively unique language, and the differences you are used to seeing between English and other Romance languages are not the relevant differences between Japanese and English. It is important to know about certain unique features before embarking on learning Japanese using Rosetta Stone, otherwise you might be extremely confused (or not even know what you're missing), which is why I don't recommend Rosetta Stone for absolute beginners. Second, even Japanese Level 3 is extremely simplistic, and Rosetta Stone does not teach many important aspects of Japanese language usage, so I would not recommend this software for advanced learners either.
Additional reviews of Rosetta Stone (Amazon won't let me link, so I'll just name them and you can Google):
- Fluent in 3 months (very detailed review, not particularly of Japanese, with responses from Rosetta Stone included)
- Tofugu (funny review with lots of interesting alternatives listed, including a free(!) Rosetta Stone clone)
- Japanese LinguaLift