Assuming you mean this Rosetta Stone: http://www.rosettastone.eu/ . I used it for a while a few years ago (they have an online version now, can't comment on that). I haven't used much other learning programs besides Memrise http://www.memrise.com/ (which I use now to learn various writing systems). So for what it's worth:
I got through the first level of Russian and Japanese, and halfway through the second level of Russian. I'd say you get a decent feeling for the language, more than I got from other attempts to learn languages. However, it never tells you _why_ something is this or that way, you always have to figure that out for yourself. For a lot of things that doesn't matter, but I kept confusing the two counting words that are used in Japanese and it didn't give a clear reason as to why you should use this one with this and that one with that.
I think it'd work well on a tablet or so, since it uses only large buttons, but back then touch screens weren't so common yet so I had to use a mouse. I think I'd like it more if I had a tablet computer to use it on. There's all kinds of fancy features like a form of speech recognition to test if you actually pronounce it properly, but I haven't used that so I can't comment on that either.
As whether it's worth the price, cough I can't comment on that. Also depends on how you have to spent ofc.
I'd say its not worth it at all though I last tried it a couple years back and don't know what the current versions are like. But if they still use the same click on a picture method, I'd say no. But it also depends on what your goals are. For me I don't care about grammer or reading because I never need to use this, all I need is to speak/understand spoken language. Anyway, I wouldn't say I'm an linguist but I speak 4 languages fluently and have learned 3 foreign ones in my life and of all courses I've ever tried the pimsleur method (http://en.wikipedia.org/wiki/Pimsleur_method) is the one I think best simulates a real language environment if you're not fortunate enough to be able to surround yourself in the language. Also I've found listening to the radio in a foreign language is a big help because you're forced to concentrate to know whats going on unlike tv.
Sorry for diverging from the topic, but I recently started learning spanish and am finding http://duolingo.com an awesome resource. The points system keeps me hooked very easily although I do find that I have to go search somewhere else for actual explanations of certain concepts.
I've used it for Spanish, Swedish and Korean. Gotta say, it's much more useful for a language where the grammar/writing system/etymology have something in common with your native language. The whole learning by intuition thing seemed to work for me with Swedish and Spanish (native English speaker) but not at all with Korean.
Rosetta Stone tends to work by slowly introducing new words, language constructs and such without explicitly telling you what they're trying to teach you. You kind of figure it out after a couple of units. But I found that while I could do that in the European languages, Korean was just too far removed from English to be able to comfortably make that leap of understanding.
I've never used Rosetta Stone, but it looks like a steep price tag.
Why don't you try some of the free online services to learn a language? After participating for 4-6 weeks, you will understand your own commitment level and then make the jump to invest in Rosetta Stone.
When I was learning french, it helped me when I watched TV in my own language and read the subtitles in the language I was learning. I would then do the reverse. Watch the show in the language I was learning and read the native language subtitles.